Design of a Symmetric CPW-Fed Patch Antenna for WLAN/WIMAX Applications Using ANN

The upper bound capacity based on the SINR model is a very important parameter when evaluating the performance of the multi-hop wireless ad hoc networks. In this paper, a new upper bound capacity algorithm is proposed. Firstly, we analyzed the classical physics SINR model over the Rayleigh fading channels to establish the relationship between density of nodes and path outage probability. Then, we developed the closed-form expression of the upper bound transmission capacity based on the Weber model for the random networks. Finally, we evaluated effects of parameters in the communication range, density, SINR threshold and fading factors, and consequently transmission capacity of the network by sensitivity analysis. The numerical simulation showed that the optimum density of nodes was existed to obtain the upper bound transmission capacity. The capacity increased firstly and then decreased over the density of nodes increasing. It affected by channel fading factor and communication range sensitively.

     

Nouvelles substances d'intercomparaison proposees pour l'etalonnage en temperature et en energie d'analyseurs thermiques (ou calorimetriques) differentiels

Several organic compounds as new reference materials for temperature and energy calibration of DTA and DSC appartuses were studied in the range of temperature 300–600 K.

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Zusammenfassung Im Temperaturbereich 300–600 K wurden einige organische Verbindungen als neue Referenzsubstanzen für die Temperatur- und Energieeichung bei DTA und DSC untersucht.

     

K2CsYb(PO4)2

The crystal structure of dipotassium caesium ytterbium bis(phosphate) is built up from regular independent PO₄ tetrahedra and YbO₆ octahedra sharing corners and arranged in layers. The structure is, in many respects, similar to that of glaserite.     

New approach for the existence of pseudo almost periodic solutions for some second order differential equation with piecewise constant argument

The following equation d²/dt²(x(t)+px(t-1))=qx(2[(t+1)/2])+f(t)${\mathrm{d}}^2/\mathrm{d}{t}^2(x(t)+\mathit{px}(t-1))=\mathit{qx}(2[(t+1)/2])+f(t)$ is considered and necessary and sufficient conditions are given in order to ensure the existence and uniqueness of pseudo almost periodic solutions.     

μ‐3,4′‐Bi‐1,2,4‐triazole‐di‐μ‐chloro‐cuivre(II) monohydraté

In the title compound, μ‐3,4′‐bi‐1,2,4‐triazole‐di‐μ‐chloro‐copper(II) monohydrate, {[CuCl₂(C₄H₄N₆)]·H₂O}_n, the Cu atom is located in a distorted octahedron consisting of two N atoms and four Cl atoms. The structural unit is an infinite chain in which octahedral groups, connected by shared edges, are also linked by bitriazole mol­ecules. The bitriazole ligand, the Cu atom and the water O atom all lie on independent twofold axes. The structure is held together by hydrogen bonds between the water mol­ecules and the non‐coordinated N atoms of the ligand, and by van der Waals forces.     

Mound morphology and growth dynamic of the wedding-cake interfaces

We aimed in this work to study numerically the scaling behavior and the mound morphological properties of the interfaces generated by the multilayer deposition process. We have found that when the diffusion process dominates strongly the deposition one, the obtained interfaces consist of wedding-cake like structures. The width of the surface is a self-affine fractal exhibiting non-trivial scaling with the surface height and the system size, and the obtained interfaces follow the Family–Vicsek law with exponent values more consisting with the Edwards–Wilkinson model.     

SnCl2/EtOH-Mediated Synthesis of Novel 4-Ethoxy- and 4-Chloroindazoles Bearing Sulfonamide Moieties

Abstract

The treatment of N-alkyl-5-nitroindazole with stannous chloride in ethanol, aftercoupling of the obtained amines with arylsulfonyl chloride in pyridine, gave the new 4-ethoxy- and 4-chloroindazoles bearing sulfonamide in moderate to good yields. Chlorination and ethoxylation of indazole were observed during the reduction of the nitro group with anhydrous SnCl₂ in ethanol. The influence of the N-alkylation in N-1 and N-2 position of 5-nitroindazole on the reduction was investigated. The presence ofethoxy group and chlorine atom at position C-4 of indazole was confirmed by x-ray diffraction analysis of compounds 7a and 8a.     

Unexpected Synthesis of Novel 3-Allyl-5-(arylidene)-2-thioxo-thiazolidin-4-ones in Reactions of 3-Allylrhodanine with 2-Arylidene-4-methyl-5-oxopyrazolidinium Ylides

Abstract

The reaction of 3-allylrhodanine with 2-arylidene-4-methyl-5-oxopyrazolidinium ylides proceeded unexpectedly to form novel 3-allyl-5-(arylidene)-2-thioxo-thiazolidin-4-ones 6a–k in good yields. All structures have been formulated on the basis of their spectral (IR, NMR, MS) data and elemental analyses. In addition, the structure of compound 6a was confirmed by means of x-ray crystallographic analysis.     

Regularity Properties of Perturbed Hille—Yosida Operators and Retarded Differential Equations

In this work we give sufficient conditions on the semigroup (T ₀ (t)) _t\geq0 , generated by the part of a Hille—Yosida operator in the closure of its domain, in order that certain perturbations preserve some regularity properties of (T ₀ (t)) _t\geq0 , like the norm continuity, compactness and differentiability. An application of our abstract results to retarded differential equations is given. May 22, 2000     

Electrochemical Sensing of Paracetamol Using 3D Porous Laser Scribed Graphene Platform

This work presents a novel disposable electrochemical sensor for paracetamol (PCM). The sensing platform is based on graphene, manufactured via laser-scribing technology (LSG) to produce a 3D-porous structure that offers a large surface area. The analytical performances of LSG electrodes were greatly enhanced due to the high catalytic activity of graphene produced by LSG technology compared to conventional carbon electrodes. Moreover, the results showed an outstanding adsorption feature towards PCM, allowing its detection at nanomolar level from 5 nM to 100 nM through pre-concentration. The proposed sensing strategy was successfully applied for the determination of PCM in human urine samples.