14 research outputs found

    Design and Modeling of Hysteresis Motor with High Temperature Superconducting Material in the Rotor using Finite Element Method

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    In this paper, a 2-pole, 50 Hz high temperature superconducting hysteresis motor with simplest construction has been numerically simulated using finite element method for its performance calculation. In this high temperature superconducting hysteresis motor, conventional stator is used and the rotor is made up of high temperature superconducting material which has the ability to trap the magnetic field as high as possible and also carries greater current densities at higher magnetic fields. Since huge investments and time are required for the practical experiments for this work, numerical simulation are preferred. The performance parameters are compared with that of the conventional hysteresis motor in which ferro-magnetic material is used as a rotor. All of these calculations are done using MATLAB based program developed in-house and PDE based module of COMSOL Multiphysics software with proper Dirichlet and Neumann boundary conditions.  The simulation result shows a good agreement with the experimental results. Keywords: High temperature superconductor (HTS), Yttrium Barium Copper Oxide (YBCO), Finite element method (FEM), Partial differential equation (PDE), COMSOL Multiphysics

    Reviewing the scope and thematic focus of 100,000 publications on energy consumption, services and social aspects of climate change: a big data approach to demand-side mitigation

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    As current action remains insufficient to meet the goals of the Paris agreement let alone to stabilize the climate, there is increasing hope that solutions related to demand, services and social aspects of climate change mitigation can close the gap. However, given these topics are not investigated by a single epistemic community, the literature base underpinning the associated research continues to be undefined. Here, we aim to delineate a plausible body of literature capturing a comprehensive spectrum of demand, services and social aspects of climate change mitigation. As method we use a novel double-stacked expert—machine learning research architecture and expert evaluation to develop a typology and map key messages relevant for climate change mitigation within this body of literature. First, relying on the official key words provided to the Intergovernmental Panel on Climate Change by governments (across 17 queries), and on specific investigations of domain experts (27 queries), we identify 121 165 non-unique and 99 065 unique academic publications covering issues relevant for demand-side mitigation. Second, we identify a literature typology with four key clusters: policy, housing, mobility, and food/consumption. Third, we systematically extract key content-based insights finding that the housing literature emphasizes social and collective action, whereas the food/consumption literatures highlight behavioral change, but insights also demonstrate the dynamic relationship between behavioral change and social norms. All clusters point to the possibility of improved public health as a result of demand-side solutions. The centrality of the policy cluster suggests that political actions are what bring the different specific approaches together. Fourth, by mapping the underlying epistemic communities we find that researchers are already highly interconnected, glued together by common interests in sustainability and energy demand. We conclude by outlining avenues for interdisciplinary collaboration, synthetic analysis, community building, and by suggesting next steps for evaluating this body of literature

    Emission Mitigation and Energy Security Trade-Off: Role of Natural Gas in the Indian Power Sector

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    India’s Nationally Determined Contributions (NDC) aim to increase the share of non-fossil fuel, especially renewables, in power generation. But at the same time, it mentions that coal is likely to dominate the power generation in the short and medium term to meet the increase in demand and support the intermittency of renewable energy-based power generation. Thus, additional efforts to transform the thermal power generation to a more efficient and less emitting one in the near term by increasing the use of natural gas (a fossil fuel with a lower emission factor than coal) may be planned towards achieving India’s additional mitigation commitments. The paper presents the implications of a proposed increase in the share of natural gas in thermal power generation of India by looking into the trade-off between emission mitigation and energy security. Along with a Reference Scenario, three alternative emission scenarios are proposed to understand the likely impacts of increased penetration of natural gas in power generation on India’s projected emission profile up to 2050. Results suggest that higher mitigation potential can be achieved through fuel-switch in thermal generation and technological up-gradation to enhance energy use efficiency. The energy security due to the increased share of natural gas imports can be dealt with by diversifying import sources. Shifts can achieve this in the emphasis on long-term contracts.publishedVersio

    Post-kala-azar dermal leishmaniasis - an overview

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    Post-kala-azar dermal leishmaniasis (PKDL) is a dermal sequela of visceral leishmaniasis (VL), reported mainly from two regions – Sudan in eastern Africa and the Indian subcontinent, with incidences of 50–60% and 5–10%, respectively. Importantly, patients with PKDL are considered as reservoirs of VL, linking its eradication to effective control of PKDL. The etiopathogenesis of PKDL is presumably due to an immunological assault on latent dermal parasites. Immunological markers include IL-10, whose expression in skin and plasma of Sudanese patients with VL predicted onset of PKDL. Cell-mediated immune responses, notably restoration of IFN-γ production by antigen-stimulated lymphocytes are well documented in Sudanese PKDL, but remain ambiguous in the Indian form; recently, antigen-specific IL-10-producing CD8+ lymphocytes have been implicated in pathogenesis. In Indian PKDL, upregulation of intralesional IFN-γ and TNF-α is counterbalanced by IL-10 and TGF-β together with downregulated IFN-γ R1. Although IL-10 curtails excessive IFN-γ-mediated reactivity and ensures parasite survival, its cellular source remains to be confirmed, with infiltrating regulatory T cells (Tregs) being a likely candidate. Future functional investigations on Tregs and their interaction with lesional effector lymphocytes would be indispensable for development of immunomodulatory therapies against Leishmania infection

    Design of an Ultra-Compact and Highly-Sensitive Temperature Sensor Using Photonic Crystal Based Single Micro-Ring Resonator and Cascaded Micro-Ring Resonator

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    Abstract In the present report, a photonic crystal based micro-ring resonator (MRR) structure is proposed which is very compact in size and has very fast response and is employed for temperature sensing purpose. Temperature sensing application for both the single MRR and cascaded MRR is illustrated in this paper. The sensitivity of the reported structure is increased from 2.9 nm/°C to 3.4 nm/°C by cascading two MRR. The refractive index of the material is subjected to change with the variation in temperature which results in the shift of the resonant wavelength of the proposed sensor. The finite difference time domain (FDTD) simulation is utilized to see the transmission spectrum of the proposed structure and analyzing the shift in the resonance wavelength the temperature is calculated. The proposed design is simple, reliable and may be integrated into different transducer and sensing applications

    Decreased frequency and secretion of CD<sub>6</sub> promotes disease progression in Indian post kala-azar dermal Leishmaniasis

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    Purpose: Leishmania, the causative organisms for leishmaniasis, reside in host macrophages and survive by modulating the microbicidal pathways via attenuation of the oxidative burst and/or suppression of cell-mediated immunity. As post kala-azar dermal leishmaniasis (PKDL), the dermal sequela of visceral leishmaniasis, has no animal model, the underlying mechanism(s) that nullify the microbicidal effector mechanisms remain poorly understood. This study was aimed at assessing the status of dipeptidyl peptidase CD26, a co-stimulatory molecule that is essential for T-cell signal activation. Methods: The frequency/expression of CD26 and CD45RO/RA was evaluated by flow cytometry, while levels of soluble CD26 (sCD26), CXCL-10, RANTES, IL-10 and TGF-β along with adenosine deaminase (ADA) activity were measured using ELISA. Results: In patients with PKDL vis-a-vis healthy individuals, there was a significant decrease in the frequency and expression of CD26 on CD3<sup>+</sup>CD8<sup>+</sup> T-cells, which was accompanied by a significant lowering of plasma levels of sCD26. Furthermore, these patients showed a significant decrease in the frequency of CD45RO<sup>+</sup>/CD8<sup>+</sup> T-cells, concomitant with a significant increase in the proportion of CD45RA<sup>+</sup>/CD8<sup>+</sup> T-cells. This could collectively translate into reduced formation of the immunological synapse of CD26, CD45RO, and ADA, and lead to an attenuation of the Th1 responses. The decreased levels of CD26 and sCD26 correlated negatively with raised levels of Th2 cytokines, IL-10, and TGF-β along with the lesional parasite load, indicating disease specificity. Conclusions: Taken together, the decreased expression and secretion of CD26 in patients with PKDL resulted in impairment of the CD26-ADA interaction, and thereby possibly contributed to T-cell unresponsiveness, emphasizing the need to develop immunomodulatory therapies against PKDL and by extension, the leishmaniases

    Evaluation of serological markers to monitor the disease status of Indian post kala-azar dermal leishmaniasis

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    Post kala-azar dermal leishmaniasis (PKDL), a dermal sequel of visceral leishmaniasis presents with macular or polymorphic lesions. As immunological variations between these two forms have not been delineated, we evaluated levels of antileishmanial total Ig, IgG and its subclasses, IgM, IgE, IgG avidity, cytokines IL-10, IL-4, IL-13 and expression of CD19. The levels of Ig and IgG in polymorphic PKDL were higher than macular PKDL, while significant curtailment in levels of Ig, IgM and IgG following treatment was evident only in polymorphic PKDL. With regard to IgG subclasses, IgG1 and IgG3 were significantly raised in polymorphic PKDL, whereas in macular PKDL only IgG1 was elevated; treatment decreased levels of IgG1, IgG2 and IgG3 only in polymorphic PKDL; IgE levels were raised in both groups but no marked alterations occurred following treatment. The avidity of IgG was higher in polymorphic PKDL and correlated with duration of disease. IL-10 was higher in polymorphic PKDL and decreased significantly after treatment, whereas in macular PKDL IL-4 predominated. Taken together, in PKDL the humoral immune response was greater in the polymorphic variant than the macular form suggesting that serological markers may have a role in monitoring polymorphic PKDL
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