This paper is presented a microstrip antenna with zig-zag feeder for wireless communication, it has wideband frequency spectrum (2-14) GHz. The proposed designed zig zag feed line which gave and acceptable gain (7.448-5.928) dB, this slots printed in the ground plane on lower side of dielectric substrate, certain form tuning stub used to increase matching between top layer substrate bottom, an ...

We analyze the phase diagram of a system of spin-1/2 Heisenberg antiferromagnetic chains interacting through a zigzag coupling, also called zigzag ladders. Using bosonization techniques we study how a spin-gap or more generally plateaux in magnetization curves arise in different situations. While for coupled XXZ chains, one has to deal with a recently discovered chiral perturbation, the couplin...

The chemisorption of pyrimidine and s-triazine, two aromatic molecules with N atoms in the aromatic ring, is studied by first principles calculations to examine not only the chemisorption energy, but also the reaction barriers and the cooperative effects. Among the reaction paths at low coverage, the formation of a cross-bridge structure with two N-Si dative bonds is almost barrierless and shou...

Spin polarized density functional theory has been used to investigate the structural stability and electronic properties of extrinsic and intrinsic defects in boron nitride nanotubes. Carbon substitutional defects under nitrogen rich and boron-rich growth conditions have the lowest heats of formation compared to boron and nitrogen antisites. Creating a defect reduces the band gap of the nanotub...

today power consumption is considered to be one of the important issues. therefore, its reduction plays a considerable role in developing systems. previous studies have shown that approximately 50% of total power consumption is used in cache memories. there is a direct relationship between power consumption and replacement quantity made in cache. the less the number of replacements is, the less...

In this study, we propose estimates for the confidence interval common mean of several zero-inflated gamma (ZIG) distributions based on fiducial generalized (GCI) and Bayesian highest posterior density (HPD) methods Jeffreys rule or uniform prior. Their performances in terms their coverage probabilities expected lengths are compared via a Monte Carlo simulation study. For almost all scenarios c...

Motivated by the work of AlFardan et al 2013, in this paper we present several results related to RC4 non-randomness in WPA. We first prove the interesting zig-zag distribution of the first byte and the similar nature for the biases in the initial keystream bytes to zero. As we note, this zig-zag nature surfaces due to the dependency of first and second key bytes in WPA/TKIP, both derived from ...

We develop an operator approach to the evaluation of multiple integrals for multiloop Feynman massless diagrams. A commutative family graph building operators $H_\alpha$ ladder diagrams is constructed and investigated. The complete set eigenfunctions corresponding eigenvalues are found. This enables us explicitly express a wide class four-point general two-loop propagator-type master diagram (w...