41 research outputs found
Noncommutative Extension of AdS-CFT and Holographic Superconductors
In this Letter, we consider a Non-Commutative (NC) extension of AdS-CFT
correspondence and its effects on holographic superconductors. NC corrections
are incorporated via the NC generalization of Schwarzschild black hole metric
in AdS with the probe limit. We study NC effects on the relations connecting
the charge density and the critical temperature of the Holographic
Superconductors. Furthermore, condensation operator of the superconductor has
been analyzed. Our results suggest that generically, NC effects increase the
critical temperature of the holographic superconductor.Comment: One figure is added, modification in formalism and noncommutative
effects emergent from star product has been removed. Results altered but main
conclusions remain unchanged. To appear in Phys.Lett.
Effects of a Maximal Energy Scale in Thermodynamics for Photon Gas and Construction of Path Integral
In this article, we discuss some well-known theoretical models where an
observer-independent energy scale or a length scale is present. The presence of
this invariant scale necessarily deforms the Lorentz symmetry. We study
different aspects and features of such theories about how modifications arise
due to this cutoff scale. First we study the formulation of energy-momentum
tensor for a perfect fluid in doubly special relativity (DSR), where an energy
scale is present. Then we go on to study modifications in thermodynamic
properties of photon gas in DSR. Finally we discuss some models with
generalized uncertainty principle (GUP).Comment: This is a review article based on our works arXiv:1002.0192,
arXiv:0908.0413, arXiv:1205.3919; v2: text overlap with gr-qc/0207085 remove
Automated Data Filtering Approach for ANN Modeling of Distributed Energy Systems: Exploring the Application of Machine Learning
To realize the distributed generation and to make the partnership between the dispatchable units and variable renewable resources work efficiently, accurate and flexible monitoring needs to be implemented. Due to digital transformation in the energy industry, a large amount of data is and will be captured every day, but the inability to process them in real time challenges the conventional monitoring and maintenance practices. Access to automated and reliable data-filtering tools seems to be crucial for the monitoring of many distributed generation units, avoiding false warnings and improving the reliability. This study aims to evaluate a machine-learning-based methodology for autodetecting outliers from real data, exploring an interdisciplinary solution to replace the conventional manual approach that was very time-consuming and error-prone. The raw data used in this study was collected from experiments on a 100-kW micro gas turbine test rig in Norway. The proposed method uses Density-Based Spatial Clustering of Applications with Noise (DBSCAN) to detect and filter out the outliers. The filtered datasets are used to develop artificial neural networks (ANNs) as a baseline to predict the normal performance of the system for monitoring applications. Results show that the filtering method presented is reliable and fast, minimizing time and resources for data processing. It was also shown that the proposed method has the potential to enhance the performance of the predictive models and ANN-based monitoring.publishedVersio
Preclinical evaluation of antihyperglycemic activity of Clerodendron infortunatum leaf against streptozotocin-induced diabetic rats
© The Author(s) 2011. This article is published with open access at Springerlink.com Introduction: Clerodendron infortunatum Linn. (Verbenaceae), commonly known as Bhant in Hindi, is a small shrub occurring throughout the plains of India, which is traditionally used for several medicinal purposes. The aim of the present stud
Characterization and Analysis of Plastic Instability in an Ultrafine‐Grained Medium Mn TRIP Steel
Herein, the mechanical and magnetic behavior of an ultrafine-grained (UFG) medium manganese (Mn) transformation-induced plasticity (TRIP) steel is focused on in its plastic instability. The in situ methods of digital image correlation (DIC) and magnetic Barkhausen noise (MBN) are used to macroscopically characterize the propagation of the Lüders band (stretcher–strain marks) and the evolution of MBN activities during quasistatic tensile deformation. The evolution of microstructure during the plastic instability is investigated ex situ using X-Ray diffraction (XRD) and transmission electron microscopy (TEM) for selected plastic strain states. It is showed in the results that the plastic instability of this steel is associated with an increase of hardness and enrichment of dislocation density, which can also amplify the MBN signal, while the derived coercivity behaves reversely on an overall trend due to work hardening. The different stress response of the medium Mn steel is closely related to the kinetic martensite microstructure, which in turn modifies the domain–structure response. Thus, the MBN can be used as a potential means for nondestructive evaluation (NDE) for the strengthening of the UFG medium Mn TRIP steel
Evolution of microstructure and texture during deformation and annealing of transformation-induced plasticity high Mn steel
An as-cast Fe-17Mn-3Al-2Si-1Ni-0.06C (wt. %) high Mn steel slab was subjected to hot rolling to 52% thickness reduction and quenched to room temperature. Thereafter, the hot-rolled plate was plane strain compressed to 5, 10, 15 and 20% thickness reductions at room temperature and cold-rolled to a further 42, 66 and 88% thickness reductions. The samples after 42% cold rolling were isochronally annealed at 500, 600, 625, 650, 700, 750, 800 and 850 °C for 300 s. Microstructure characterisation was undertaken via electron back-scattering diffraction (EBSD), conventional, high-resolution scanning and in-situ transmission electron microscopy (TEM). Mechanical behaviour was investigated using a combination of uniaxial tensile testing and digital image correlation on dog-bone samples after 42% cold rolling and annealing at 500, 625, 650, 700 and 800 °C
Additively Manufactured Nested and Non-Nested Cellular Solids for Effective Stress Distribution and Thermal Insulation Applications: An Experimental and Finite Element Analysis Study
In this study, the design, additive manufacturing and experimental as well as simulation investigation of mechanical and thermal properties of cellular solids are addressed. For this, two cellular solids having nested and non-nested structures are designed and additively manufactured via laser powder bed fusion. The primary objective is to design cellular solids which absorb a significant amount of energy upon impact loading without transmitting a high amount of stress into the cellular solids. Therefore, compression testing of the two cellular solids is performed. The nested and non-nested cellular solids show similar energy absorption properties; however, the nested cellular solid transmits a lower amount of stress in the cellular structure compared to the non-nested cellular solid. The experimentally measured strain (by DIC) in the interior region of the nested cellular solid is lower despite a higher value of externally imposed compressive strain. The second objective of this study is to determine the thermal insulation properties of cellular solids. For measuring the thermal insulation properties, the samples are placed on a hot plate; and the surface temperature distribution is measured by an infrared camera. The thermal insulating performance of both cellular types is sufficient for temperatures exceeding 100 °C. However, the thermal insulating performance of a non-nested cellular solid is slightly better than that of the nested cellular solid. Additional thermal simulations predict a relatively higher temperature distribution on the cellular solid surfaces compared to experimental results. The simulated residual stress shows a similar distribution for both types, but the magnitude of residual stress is different for the cellular solids upon cooling from different temperatures of the hot plate