703 research outputs found

    Competition between Superconductivity and Charge Density Wave Ordering in the Lu5_5Ir4_4(Si1x_{1-x}Gex_x)10_{10} Alloy System

    Full text link
    We have performed bulk measurements such as dc magnetic susceptibility, electrical resistivity and heat capacity on the pseudo-ternary alloys Lu5_5Ir4_4(Si1x_{1-x}Gex_x)10_{10} to study the interplay and competition between superconductivity and the charge density wave (CDW) ordering transition. We track the evolution of the superconducting transition temperature TSC_{SC} and the CDW ordering temperature TCDW_{CDW} as a function of x (concentration of Ge) (0.0x 1.00.0 \leq x\leq~1.0). We find that increasing x (increasing disorder) suppresses the TCDW_{CDW} rapidly with the concomitant increase in TSC_{SC}. We present a temperature-concentration (or volume) phase diagram for this system and compare our results with earlier work on substitution at the Lu or Ir site to show how dilution at the Si site presents a different situation from these other works. The heat capacity data in the vicinity of the CDW transition has been analyzed using a model of critical fluctuations in addition to a mean-field contribution and a smooth lattice background. We find that the critical exponents change appreciably with increasing disorder. This analysis suggests that the strong-coupling and non mean-field like CDW transition in the parent compound Lu5_5Ir4_4Si10_{10} changes to a mean-field like transition with increasing Ge concentration.Comment: 14 pages and 8 figures. Accepted for publication in Phys. Rev.

    Inverter current control for reactive power compensation in solar grid system using Self-Tuned Fuzzy Logic Controller

    Get PDF
    The solar photovoltaic (PV) systems have gained more attention in renewable energy production due to their cost efficiency and reliability. Typically, reactive power compensation and harmonics elimination are challenging and demanding tasks for improving the efficacy of grid-connected solar PV systems. For this purpose, many research works developed different converter and controller topologies for solving the power quality issues in grid-PV systems. But, it limits the problems of increased harmonics, computation complexity, inefficiency and reduced performance outcomes. Thus, this research aims to develop an integrated hysteresis current controller and Self-Tuned Fuzzy Logic (SFLC) based MPPT controllers for eliminating the harmonics and unbalanced current in single-phase grid systems. Also, it helps to extract the maximum amount of power from the solar PV array. The LUO converter is deployed to reduce ripple contents. The Phased Locked Loop (PLL) based synchronization is performed to maintain the phase angle, frequency and magnitude levels of source power. Moreover, the hysteresis current controller for the inverter has been specifically designed to reduce the THD of the system under IEEE519_1992 regulations. During experiments, both the simulation and hardware results have been evaluated for validating the performance of the proposed controller design

    Certain Subclasses Of Meromorphic Functions With Fixed Second Coefficients Associated With Generalized Polylogarithm Functions

    Get PDF
    In this paper we introduce and study a subclass GP (α, λ, μ, κ, c) of meromorphic univalent functions which is associated with generalized polylogarithm functions. We obtain coefficient estimates, extreme points, growth and distortion bounds, radii of meromorphically starlikeness and meromorphically convexity for the class GP (α, λ, μ, κ, c) by fixing the second coefficient. Further, it is shown that the class GP (α, λ, μ, κ, c) is closed under convex linear combination

    Magnetic and Transport Properties of Ternary Indides of type R2CoIn8 (R = Ce, Pr and Dy)

    Full text link
    We have synthesized and investigated the magnetic and transport properties of a series of compounds, R2CoIn8 (R = rare earth). Compounds form in single phase with a tetragonal structure (space group P4/mmm, no. 162). The Ce compound shows heavy fermion behavior. The magnetic susceptibility of Pr2CoIn8 shows a marked deviation from the Curie-Weiss behavior at low temperatures, which is attributed to the crystalline electric field effects. Heat capacity and magnetization measurements show that Dy2CoIn8 undergoes a magnetic transition at 17 K and a second transition near 5 K, the latter of which may be due to spin reorientation. Magnetization of this compound shows two metamagnetic transitions approximately at 3.6 T and 8.3 T.Comment: Total 7 pages of text and figure

    Prospecting for scarabid specific Bacillus thuringiensis crystal toxin cry8 gene in sugarcane ecosystem of Tamil Nadu, India

    Get PDF
    In the present study, we report the occurrence of cry8 positive isolates of Bacillus thuringiensis (Bt) in selected white grub, Holotrichia serrata F. (Coleoptera: Scarabaeidae), endemic soils of sugarcane ecosystem and other places in Tamil Nadu. Out of the 66 soil samples collected and screened for white grub specific Bt, 74 isolates of the bacterium, all containing only spherical crystal toxin, were identified. PCR screening of these isolates with cry8 gene universal primer revealed six isolates to be positive. Further, the amplicon of a 370 bp band, amplified with another set of degenerate primer designed based on the conserved sequence of cry8 genes, was sequenced from four isolates. Multiple sequence alignment revealed the gene sequences to be the same for all the isolates. The present report of the availability of cry8 positive Bt isolates opens the avenue for controlling white grubs through transgenic research

    Retinal Image Analysis: A Review

    Get PDF
    Images of the eye ground or retina not only provide an insight to important parts of the visual system but also reflect the general state of health of the entire human body. Automated retina image analysis is becoming an important screening tool for early detection of certain risks and diseases like diabetic retinopathy, hypertensive retinopathy, age related macular degeneration, glaucoma etc. This can in turn be used to reduce human errors or to provide services to remote areas. In this review paper, we discuss some of the current techniques used to automatically detect the important clinical features of retinal image, such as the blood vessels, optic disc and macula. The quantitative analysis and measurements of these features can be used to better understand the relationship between various diseases and the retinal features

    Methyl 3-(4-bromo­phen­yl)-1-methyl-1,2,3,3a,4,9b-hexa­hydro­benzo[f]chromeno[4,3-b]pyrrole-3a-carboxyl­ate

    Get PDF
    In the title compound, C24H22BrNO3, the dihydro­pyran ring adopts a half-chair conformation, whereas the pyrrolidine ring is in an envelope conformation. The bromo­phenyl group is oriented at an angle of 66.44 (4)° with respect to the naphthalene ring system. In the crystal structure, mol­ecules are linked into centrosymmetric dimers by C—H⋯π inter­actions and the dimers are connected via C—H⋯Br hydrogen bonds. The crystal structure is further stabilized by π–π inter­actions [centroid–centroid distance = 3.453 (1) Å]
    corecore