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101.
Rajkumar P. Diwakar K. Subadevi R. Gnanamuthu R. M. Wang Fu-Ming Liu Wei-Ren Sivakumar M. 《Journal of Solid State Electrochemistry》2021,25(3):939-948
Journal of Solid State Electrochemistry - The “shuttle effect” of polysulfides is a serious issue, resulting in a decrease in the life-cycle of lithium-sulfur (Li-S) batteries. To... 相似文献
102.
Budigi Lokesh Nasina Madhusudhana Rao Shaik Kaleemulla Amaravadi Sivakumar 《Chemical Papers》2015,69(11):1481-1490
The freeze-drying method of metal oxides synthesis has a number of advantages such as high homogeneity, varying porous structures, morphologies and uniform particle size distribution, etc. Because of these advantages, the binary metal oxides ZnO, TiO2 and ternary metal oxide ZnTiO3 were synthesised by the freeze-drying method. The synthesised materials were characterised by X-ray diffraction (XRD), Fourier transform-infra red spectroscopy (FT-IR), UV-VIS spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The as-synthesised metal oxides were calcined at different temperatures to study the phase evolution and morphological changes. The crystalline cubic-phase ZnTiO3 (a = 8.3948 Å) was obtained on calcination of the precursor at 600°C, and decomposed to the cubic phase Zn2TiO4 (a = 8.4580 Å) and rutile TiO2 (a = 4.5955 Å and c = 2.9593 Å) at 1000°C. The band gap of ZnO (3.28?3.10 eV), TiO2 (3.37?2.97 eV) and ZnTiO3 (3.92?3.80 eV) calculated using Tauc’s relation was found to vary inversely with calcination temperature and phase transition. 相似文献
103.
Sivakumar Bakthavachalu Miguel A. Labrador 《International Journal of Communication Systems》2004,17(8):763-778
The TFRC protocol has been proposed as a TCP‐friendly protocol to transport streaming media over the Internet. However, its deployment is still questionable because it has not been compared to other important protocols, analysed in the presence of important mechanisms, such as the explicit congestion notification (ECN), and studied under more realistic network conditions. In this paper, we address these three aspects, including other congestion control protocols not considered before in the same investigation, such as TCP Tahoe, Reno, Newreno, Vegas, Sack, GAIMD, and the Binomial algorithms, the effect of using ECN in the friendliness of the protocols, and the fairness of the protocols under static and dynamic network conditions. We found that TFRC can be safely deployed in the Internet if competing with TCP Tahoe, New Reno and SACK since fairness is achieved under all scenarios considered. We also found that ECN actually helps in achieving better fairness. However, fairness problems arise when TFRC competes with TCP Reno, GAIMD, SQRT or IIAD in static or dynamic conditions, or both. We used normalized throughput, fairness index, and convergence time as the main performance metrics for comparison. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
104.
Single crystals of the nonlinear material γ-glycine have been grown in the presence of lithium nitrate by slow-evaporation method. Structural characterization of the grown crystals was carried out by powder and single crystal X-ray diffraction (XRD) methods and it is observed that the samples crystallize in hexagonal system with non-centrosymmetric space groups. The modes of vibrations of different molecular groups present in glycine have been identified by spectral analyses. UV–visible transmittance study was performed to analyze optical transparency of γ-glycine crystals and found that the crystal was transparent in the entire visible-NIR region. Second harmonic generation (SHG) conversion efficiency has been estimated as 62 mV and the output power by the crystal was 1.72 times that of potassium dihydrogen phosphate (KDP) crystal. The thermal stability and decomposition of the sample have been studied by thermal analysis and it is observed that the γ-glycine crystal have good thermal stability. 相似文献
105.
Two new vanadates, Ba(2.5)(VO2)3(SeO3)4.H2O and La(VO2)3(TeO6).3H2O, have been synthesized by hydrothermal methods using BaCO3, Ba(OH)2.H2O, La(NO3)3.6H2O, V2O5, TeO2, and H2SeO3 as reagents. The structures were determined by single-crystal X-ray diffraction. Ba(2.5)(VO2)3(SeO3)4.H2O exhibits a two-dimensional layered structure consisting of VO(5) square pyramids and SeO3 polyhedra, whereas La(VO2)3(TeO6).3H2O has a three-dimensional framework structure composed of VO(4) tetrahedra and TeO6 octahedra. Infrared and Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, and thermogravimetric analysis are also presented. Crystal data: Ba(2.5)(VO2)3(SeO3)4.H2O, trigonal, space group P (No. 147) with a = b = 12.8279(15) A, c = 7.2631(9) A, V = 1035.1(2) A(3), and Z = 2; La(VO2)3(TeO6).3H2O, trigonal, space group R3c (No. 161) with a = b = 9.4577(16) A, c = 23.455(7) A, V = 1816.9(7) A3, and Z = 6. 相似文献
106.
The concept of the Moore-Penrose inverse in an indefinite inner product space is introduced. Extensions of some of the formulae in the Euclidean space to an indefinite inner product space are studied. In particular range-hermitianness in completely characterized. Equivalence of a weighted generalized inverse and the Moore-Penrose inverse is proved. Finally, methods of computing the Moore-Penrose inverse are presented. 相似文献
107.
Santhanam Sivakumar Ayyasamy Selvaraj Anaipalayam Kandasamy Ramasamy 《Photochemistry and photobiology》2013,89(5):1047-1056
In this study, the photocatalytic degradation of organic reactive dyes have been investigated using MnTiO3/TiO2 heterojunction composites in the presence of electron acceptors under UV‐Visible light irradiation. This MnTiO3/TiO2 heterojunction composites were prepared by annealing different mass ratios of pyrophanite MnTiO3 (3–11 wt%) and TiO2 at 300°C. All the MnTiO3/TiO2 heterojunction composites were characterized by spectral techniques like X‐ray diffraction (XRD), scanning electron microscope (SEM) and diffused reflectance UV‐visible spectroscopic analysis (DRS). Among them, 9 wt% MnTiO3/TiO2 heterojunction composites exhibited higher photocatalytic activity for the degradation of Reactive Blue 4 (RB 4). The photocatalytic efficiency of 9 wt% MnTiO3/TiO2 heterojunction composites was further enhanced by the addition of substantial amount of electron acceptors like hydrogen peroxide (H2O2) and ammonium peroxydisulfate ([NH4]2S2O8). The presence of oxidants (electron acceptors) facilitates the fast degradation of dye solution even in higher concentration upto 200 mg/L. The photocatalytic activity of MnTiO3/TiO2 heterojunction composites was also studied for the degradation of other four different structured reactive dyes. The extent of mineralization of these organic reactive dyes during photocatalytic degradation was estimated from COD analysis. MnTiO3/TiO2 heterojunction composites was also found to have good photostability in the presence of oxidants. 相似文献
108.
Fabrication of planar gratings by direct ablation using an ultrashort pulse laser in a common optical path configuration 总被引:4,自引:0,他引:4
K. Venkatakrishnan N.R. Sivakumar B. Tan 《Applied Physics A: Materials Science & Processing》2003,76(2):143-146
Planar gratings have wide applications and to date, many methods for the fabrication of gratings have been reported. Ultrashort
pulse lasers have been used for the machining of gratings primarily because they allow direct ablation and the manufacturing
of sub-wavelength structures. In this paper, we present a novel direct ablation technique for the fabrication of planar gratings
which makes use of the interference of ultrashort pulses in a common optical path configuration. This technique of grating
fabrication not only simplifies the optical setup, but also immunizes the system to extraneous and inherent vibrations, thus
enabling the manufacturing of planar gratings of good edge acuity. We have successfully fabricated planar gratings on a copper
substrate.
Received: 6 November 2001 / Accepted: 4 March 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +65/77-904-674, E-mail: mvenkata@ntu.edu.sg 相似文献
109.
Abdelsalam Ahmed M. Elsheikh Ahmed Chidambaram Sivakumar David Jean-Pierre Langlois J. M. Pierre 《Journal of Signal Processing Systems》2020,92(1):95-107
Journal of Signal Processing Systems - Convolutional Neural Networks (CNNs) and Deep Neural Networks (DNNs) have gained significant popularity in several classification and regression applications.... 相似文献
110.