Miniaturized Trapezoidal Patch Antenna with Folded Ramp-Shaped Feed for Ultra-Wideband Applications

A novel design for compact probe-fed wideband microstrip patch antenna for ultra-wideband (UWB) applications is proposed in this paper. The antenna consists of a folded ramp-shaped feed, trapezoidal patch and shorting pins. By adding two pins at end side of the patch, its size is miniaturized. The measured impedance bandwidth (VSWR  $\le $  2) of fabricated antenna is more than 130 % from 3.7 to 17.6 GHz. This antenna achieves an acceptable miniaturization and provides an excellent UWB impedance bandwidth with stable radiation patterns. It is shown by simulated results how the bandwidth can be considerably increased by introducing novel feeding method namely, the folded ramp-shaped feed. Likewise, the parametric study is performed to describe the characteristics of the proposed antenna. Moreover, good antenna performances such as radiation patterns, acceptable miniaturization and antenna gains over the operating band have been observed.     

Theoretical study of the effects of substitution,solvation, and structure on the interaction between nitriles and methanol

We report an investigation on intermolecular interactions in R? CN ··· H? OCH₃ (R = H, CH₃, F, Cl, NO₂, OH, SH, SCH₃, CHO, COCH₃, CH₂Cl, CH₂F, CH₂OH, CH₂COOH, CF₃, SCOCH₃, SCF₃, OCHF₂, CH₂CF₃, CH₂OCH₃, and CH₂CH₂OH) complexes using density functional theory. The calculations were conducted on B3LYP/6‐311++G** level of theory for optimization of geometries of complexes and monomers. An improper hydrogen bonding (HB) in the H₃CO? H ··· NC? R complexes was observed in that N atom of the nitriles functions acts as a proton acceptor. Furthermore, quantum theory of “Atoms in Molecules” (AIM) and natural bond orbital (NBO) method were applied to analyze H‐bond interactions in respective complexes. The electron density (ρ) and Laplacian (?²ρ) properties, estimated by atoms in molecules calculations, indicate that H ··· N bond possesses low ρ and positive ?²ρ values, which are in agreement with partially covalent character of the HBs, whereas O? H bonds have negative ?²ρ values. In addition, the weak intermolecular force due to dipole–dipole interaction (U) is also considered for analysis. The examination of HB in these complexes by quantum theory of NBO method fairly supports the ab initio results. Natural population analysis data, the electron density, and Laplacian properties, as well as, the ν(O? H) and γ(O? H) frequencies of complexes, calculated at the B3LYP/6‐311++G** level of theory, are used to evaluate the HB interactions. The calculated geometrical parameters and conformational analysis in water phase solution show that the H₃CO? H ··· NC? R complexes in water are more stable than that in gas phase. The obtained results demonstrated a strong influence of the R substituent on the properties of complexes. Numerous correlations between topological, geometrical, thermodynamic properties, and energetic parameters were also found. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012     

Horseradish Peroxidase as a Catalyst for Atom Transfer Radical Polymerization

The hemoprotein horseradish peroxidase (HRP) catalyzes the polymerization of N‐isopropylacrylamide with an alkyl bromide initiator under conditions of activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) in the absence of any peroxide. This is a novel activity of HRP, which we propose to name ATRPase activity. Bromine‐terminated polymers with polydispersity indices (PDIs) as low as 1.44 are obtained. The polymerization follows first order kinetics, but the evolution of molecular weight and the PDI upon increasing conversion deviate from the results expected for an ATRP mechanism. Conversion, and PDI depend on the pH and on the concentration of the reducing agent, sodium ascorbate. HRP is stable during the polymerization and does not unfold or form conjugates.

     

On Supervised Classification of Feature Vectors with Independent and Non-Identically Distributed Elements

In this paper, we investigate the problem of classifying feature vectors with mutually independent but non-identically distributed elements that take values from a finite alphabet set. First, we show the importance of this problem. Next, we propose a classifier and derive an analytical upper bound on its error probability. We show that the error probability moves to zero as the length of the feature vectors grows, even when there is only one training feature vector per label available. Thereby, we show that for this important problem at least one asymptotically optimal classifier exists. Finally, we provide numerical examples where we show that the performance of the proposed classifier outperforms conventional classification algorithms when the number of training data is small and the length of the feature vectors is sufficiently high.     

Determining organo-chemical composition of sugarcane bagasse-derived biochar as a function of pyrolysis temperature using proximate and Fourier transform infrared analyses

Journal of Thermal Analysis and Calorimetry - Effect of thermal energy storage (TES) system of solar updraft tower (SUT) is studied in this work. A 3D numerical model was developed to analyze the...     

Werner's Syndrome: A Rare Cause of Hoarseness

Werner's syndrome (WS) is a rare hereditary disorder which is characterized by clinical signs of premature aging. A 31-year-old man presented with a 12-year history of hoarseness. Also noted were diabetes mellitus, cataracts, scleroderma-like skin atrophy, osteoporosis, and hypogonadism. A clinical diagnosis of WS was made. Laryngoscopy revealed bowed vocal folds resulting in a spindle-shaped closure with glottal incompetence during phonation. We used Gortex for medialization of the middle part of vocal fold to correct the glottal gap in this patient. Despite correction of glottal incompetence in patients with WS, quality of voice could not be improved to that of age-matched normal individuals.     

Dynamical analysis and anti-oscillation-based adaptive control of the FO arch MEMS with optimality

Nonlinear Dynamics - This paper mainly investigates dynamical analysis and anti-oscillation-based adaptive control issues of the fractional-order (FO) arch microelectromechanical system (MEMS) with...