Microstrip antenna with DGS based on CSRR array for WiMAX applications

This paper reports a novel method for designing a miniaturized microstrip antenna with DGS based on CSRR array which operates in the frequency of 2.6GHz for low band WiMAX application. The proposed antenna is designed using ANSYS HFSS simulation software. The antenna with optimized parameters is fabricated using FR-4 substrate of thickness 1.6 mm. The simulated and measured performances of the antenna in terms of return loss, directivity and radiation patterns are presented in this work. When Complimentary Split Ring Resonators (CSRRs) array are placed on the ground plane, the resonant frequency is shifted  to a lower value and patch size is reduced .The measurements were taken and compared with the simulated results. The performance characteristics obtained from the measurements show that the proposed antenna is suited for WiMAX application at 2.6GHz

Experimental Investigations & Effects of Cutting Variables on MRR and Tool Wear for AISI S2 Tool Steel

AbstractMachining is the most important of the manufacturing processes which involves the process of removing material from a work piece in the form of chips. Machining is necessary where tight tolerances on dimensions and finishes are required. Generally a machining process involves a large number of variables that affect its performance. Some of them are cutting parameters, geometry of cutting tool, coolant conditions, properties of tool material, properties of work piece, machine capabilities, etc. Among them, cutting parameters have profound effect on all kinds of performances when the same tool material and the same work piece material are used for machining. Therefore cutting parameters of speed, feed and depth of cut are considered as the process control variables and two important performance measures of CNC turning, namely, Metal Removal Rate (MRR) and Tool wear (TW) are considered for investigation. This paper presents the experimental investigations on the effects of cutting variables like Spindle speed, Feed and Depth of cut on the Material removal rate and tool wear. The experiments were conducted on AISI S2 tool steel grade on a CNC turning machine using carbide insert. The experiments were conducted as per the design of experiments. Initial trial experiments were conducted to fix the ranges for the control parameters. After conducting the experiments the MRR and Tool wear were measured and recorded. The effects were studied after plotting the graphs between the Input process parameters versus the responses using Design expert software. The results obtained in this study can by further used for optimizing the process parameters there by the optimized results help the operator to enhance the quality as well as machining rate

Truncated Microstrip Patch Antenna with DGS Based on Double Looped CSRR Arrays for Enhancement of Bandwidth

This paper presents a novel method for the design of truncated microstrip patch antenna with DGS based on Double Looped CSRR arrays for enhancement of bandwidth. The proposed antenna is suitable for WLAN/Wi-Fi, RFID applications. A truncated microstrip patch antenna without DGS was initially designed for a resonant frequency of 2.86GHz having a bandwidth of 95.6MHz. By integrating a new Double Looped CSRR array (DLCSRR) structure on the ground plane, resonant frequency of the antenna is shifted to 2.47GHz and also the bandwidth is enhanced to 202.5MHz. By implementing DLCSRR array structure on the ground plane size reduction and bandwidth enhancement of 52.79% is achieved. The performance of truncated microstrip patch antenna with DGS based on Double Looped CSRR array structure was also compared by replacing conventional proximity fed microstrip patch antenna with the same physical size. The conventional proximity coupled microstrip patch antenna is designed for a resonant frequency of 2.26GHz with a lower bandwidth of 23.3MHz.The antennas were designed using CST simulation software. The measurement  result shows a good agreement with simulated results

Anomalous Thermoelectric power of over-doped Bi2Sr2CaCu2O8 superconductor

Temperature dependence of thermoelectric power S(T) of three differently processed Bi2Sr2CaCu2O8 (Bi2212) samples, viz. as-processed melt quenched (Bi2212-MQ), 6000C N2-annealed (Bi2212-N2) and 6000C O2-annealed (Bi2212-O2) is reported here. All the samples possess single-phase character and their superconducting transition temperatures (TcR=0) are 85 K, 90 K and 72 K respectively for Bi2212-MQ, Bi2212-N2 and Bi2212-O2. While Bi2212-MQ and Bi2212-N2 samples are in near optimum doping regime, Bi2212-O2 is an over-doped sample. TcS=0 values obtained through S(T) data are also in line with those deduced from the temperature dependence of resistance and DC magnetization. Interestingly, S(T) behaviour of the optimally-doped Bi2212-MQ and Bi2212-N2 samples is seen to be positive in whole temperature range, it is found negative for the over-doped Bi2212-O2 sample above TcS=0. These results have been seen in the light of the recent band structure calculations and the ensuing split Fermi surface as determined by angle-resolved photoelectron spectroscopy (ARPES).Comment: 11 Pages Text + Figs: comments welcome ([email protected]

Non parametric measures to estimate GxE interaction of dual purpose barley genotypes for grain yield under multi-location trials

GxE interaction of seventeen dual purpose barley genotypes evaluated at ten major barley locations of the country by non parametric methods. Non parametric measures had been well established and expressed ad-vantages over their counter parts i.e. parametric measures. Simple descriptive measures based on the ranks of gen-otypes i.e. Mean of ranks (MR) pointed towards RD2925 and BH1008 and standard deviation of ranks (SD) for KB1401 and UPB1054 whereas Coefficient of variation (CV) for JB322 and RD2925 as stable genotypes. Nonpara-metric measures based on original values (Si1, Si2, Si3, Si4, Si5, Si6, Si7) indicated the stable performance of NDB1650, JB322 and UPB1054 while UPB1053, RD2715, RD2927 and RD2035 were observed of unstable nature. CSi1, CSi2, CSi3, CSi4, CSi5, CSi6 and CSi7 measures based on the ranks of corrected grain yield identified JB322, RD2552, RD2925 and NDB1650 as stable genotypes. Spearman’s rank correlation established highly significant positive correlation of yield with SD (0.67), Si1(0.65), Si2(0.59), Si5(0.68), Si7(0.67) whereas negative association observed for CMR (Mean of corrected ranks) (-0.62), CMed (Median of corrected ranks) (-0.60). NPi(2) expressed negative correlation with CV(-0.32), Si6 (-0.30), CMR(-0.34) and CMed(-0.48). More over NPi(3) maintained negative correlation with most of the measures though the magnitude was of low magnitude

Extrapolation of Multiplicity distribution in p+p(\bar(p)) collisions to LHC energies

The multiplicity (N_ch) and pseudorapidity distribution (dN_ch/d\eta) of primary charged particles in p+p collisions at Large Hadron Collider (LHC) energies of \sqrt(s) = 10 and 14 TeV are obtained from extrapolation of existing measurements at lower \sqrt(s). These distributions are then compared to calculations from PYTHIA and PHOJET models. The existing \sqrt(s) measurements are unable to distinguish between a logarithmic and power law dependence of the average charged particle multiplicity () on \sqrt(s), and their extrapolation to energies accessible at LHC give very different values. Assuming a reasonably good description of inclusive charged particle multiplicity distributions by Negative Binomial Distributions (NBD) at lower \sqrt(s) to hold for LHC energies, we observe that the logarithmic \sqrt(s) dependence of are favored by the models at midrapidity. The dN_ch/d\eta versus \eta for the existing measurements are found to be reasonably well described by a function with three parameters which accounts for the basic features of the distribution, height at midrapidity, central rapidity plateau and the higher rapidity fall-off. Extrapolation of these parameters as a function of \sqrt(s) is used to predict the pseudorapidity distributions of charged particles at LHC energies. dN_ch/d\eta calculations from PYTHIA and PHOJET models are found to be lower compared to those obtained from the extrapolated dN_ch/d\eta versus \eta distributions for a broad \eta range.Comment: 11 pages and 13 figures. Substantially revised and accepted for publication in Journal of Physics

Heavy Flavour Baryons in Hyper Central Model

Heavy flavor baryons containing single and double charm (beauty) quarks with light flavor combinations are studied using the hyper central description of the three-body problem. The confinement potential is assumed as hyper central coulomb plus power potential with power index $\upsilon$. The ground state masses of the heavy flavor, $J^P={1/2}^+$ and ${3/2}^+$ baryons are computed for different power index, $\nu$ starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value in each case of quark combinations beyond the power index $\nu=1.0$.Comment: 10 pages, 4 figure

Magnetization hysteresis and time decay measurements in FeSe0.50_{0.50}Te0.50_{0.50} : Evidence for fluctuation in mean free path induced pinning

We present results of magnetic measurements relating to vortex phase diagram in a single crystal of FeSe$_{0.5}$Te$_{0.5}$ which displays second magnetization peak anomaly for $H \parallel c$. The possible role of the crystalline anisotropy on vortex pinning is explored via magnetic torque magnetometry. We present evidence in favor of pinning related to spatial variations of the charge carrier mean free path leading to small bundle vortex pinning by randomly distributed (weak) pinning centers for both $H \parallel c$ and $H \perp c$. This is further corroborated using magnetization data for $H \parallel c$ in a single crystal of FeSe$_{0.35}$Te$_{0.65}$. Dynamical response across second magnetization peak (SMP) anomaly in FeSe$_{0.5}$Te$_{0.5}$ has been compared with that across the well researched phenomenon of peak effect (PE) in a single crystal of CeRu$_2$.Comment: 11 figures, provided additional data in another sample, added Fig.

Circularly Polarized Split Ring Resonator Loaded Slot Antenna

A compact circularly polarized printed slot antenna operating at 2.45 GHz is reported. The antenna consists of a pair of rotated square split ring resonators (SRR) inside a rectangular slot etched on the ground plane of an FR-4 dielectric substrate. A microstrip open-loop feed is etched on the backside of the dielectric substrate to feed the slot and the split ring resonators. The overall size of the antenna is 60x42x1.6 mm3. The measured -10dB impedance bandwidth is 10.48% (2.38-2.64 GHz) and the measured 3dB axial ratio (AR) bandwidth covers the entire impedance bandwidth