A simple one-pot procedure for the direct conversion of alcohols into alkyl nitriles using TsIm

A convenient and efficient one-pot preparation of nitriles from alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, treatment of alcohols with a mixture of NaCN, TsIm and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in refluxing DMF furnishes the corresponding alkyl nitriles in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.     

UWB body area network channel modeling: An analytical approach

The aim of this work is to develop an analytically-based approach for ultra wide band (UWB) body area network (BAN) channel modeling. In detail, the body will be modeled as multi-layered stratified cylinders of infinite length, and the Maxwell's equation will be solved for plane wave and line source excitations. Human-type tissues will be assumed in the multi-layered stratified cylindrical model. Validation of the procedure through measurement results has been provided.     

Automatic selection and fusion of color spaces for image thresholding

Automatic selection of color models has a great significance for machine vision purposes like image segmentation, object recognition, etc. Typically, selection of a proper color model is a problem that can just solve by testing the models on the target one by one. To achieve a proper color model, in this article, we propose a new method which is shaped on the basis of clustering and relation among models. The proposed method is verified experimentally for two different images (in thresholding purpose). The experimental results show that this method has a suitable power for automatic purposes.     

Semantic image classification by genetic algorithm using optimised fuzzy system based on Zernike moments

Image classification is a challenging problem of computer vision. This study reports a fuzzy system to semantic image classification. As it is a complex task, various information of digital image, including three color space components and two Zernike moments with different order, are gathered and utilized as an input of fuzzy inference system to materialize a robust rotation/lighting condition and size invariant image classifier. For better performance, all the membership functions are optimized by genetic algorithm after empirical design stage. 90.62 and 96.25 % classification rates for RGB and HSI color spaces confirm the reliability of optimized system in different image conditions given in this contribution.     

Heterocycle-bridged and Conformationally Constrained Retinoids: Synthesis of 4-(7,8,9,10-Tetrahydro-7,7,10,10-tetramethyl-4H-benzo[6,7]chromeno-[4,3-d]thiazole-2-yl)benzoic Acid

Retinoids are a class of synthetic and natural compounds structurally related to retinoic acid. In a search for discovery of a new class of heterocycle‐bridged and conformationally constrained retinoids, here we report the synthesis of 4‐(7,8,9,10‐tetrahydro‐7,7,10,10‐tetramethyl‐4H‐benzo[6,7]chromeno[4,3‐d]thiazole‐2‐yl)benzoic acid ( 10 ) starting from 5,6,7,8‐tetrahydro‐5,5,8,8‐tetramethylnaphthalen‐2‐ol ( 13 ). Several approaches was attempted to obtain target compound 10 . Structure elucidation of synthesized compounds has been made on the basis of elemental analysis and spectral data (¹H NMR, IR and MS).     

Synthesis of Acyclic Nucleosides with N‐[(Benzyloxy)(aryl)methyl] Substituents as Potential HEPT,EBPU, and TNK‐651 Analogues

The syntheses of the novel acyclic nucleosides 5a – 5m , carrying different N‐[(benzyloxy)(aryl)methyl] substituents, are described (Scheme). These compounds could be prepared in medium‐to‐good yields by either direct or silyl‐assisted coupling of the electrophiles 6 with either purine or pyrimidine nucleobases, or with different imidazole derivatives. The reactivity of the positively charged electrophilic intermediates derived from 6 upon Cl^? abstraction was rationalized by ab initio HF/6‐311G quantum‐mechanic calculations. The positive charge was found to be dispersed differently, depending on the electronic properties of the aryl substituents.     

Automated sperm immobilization for intracytoplasmic sperm injection

Sperm immobilization is a requisite step in intracytoplasmic sperm injection (ICSI). Conventionally, sperm immobilization is performed manually, which entails long training hours and stringent skills. Manual sperm immobilization also has the limitation of low success rates and poor reproducibility due to human fatigue and skill variations across operators. This paper presents a system for fully automated sperm immobilization to eliminate limitations in manual operation. Integrating computer vision and motion control algorithms, the automated system is able to visually track a sperm and control a micropipette to immobilize the sperm. A robust sperm tail tracking algorithm is developed to locate the optimal position on the sperm tail for sperm immobilization. The system demonstrates: 1) an average sperm tail tracking error of 0.95 μm; 2) a sperm tail visual tracking success rate of 96%; 3) a sperm immobilization success rate of 88.2% (based on 1000 trials); and 4) a speed of 6-7 s per successful immobilization.     

Thermal and morphological characteristics of solution blended epoxy/NBR compound

Systematic study about the effect of acrylonitrile–butadiene rubber (NBR) concentration on the fracture toughness and thermal behavior of epoxy resin is conducted in this study. NBR is solved in an aromatic hydrocarbon solvent and is added to epoxy resin. We used diethylene-teriamin as the curing agent for epoxy resin. Tensile test results, performed followed by molding procedure, show that the toughness is improved owing to the increase of rubber content. Scanning electron microscopy (SEM) and atomic force microscopy besides thermogravimetric analysis (TG) are used to investigate the epoxy/rubber interface and chemical decomposition of the resultant mixture. The thermal behavior of cured epoxy resin was analyzed via TG instrument at different heating rates. Thermogravimetry curves showed that the thermal decomposition of epoxy system was occurred in only one stage regardless of the rubber content. The apparent activation energies of the rubber/epoxy systems containing 0, 5, and 10 phr of rubber were determined by Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Friedman methods. The results prove that the thermal stability of epoxy resin was decreased with enhancing the rubber content. However, the trend of changing activation energy versus conversions is totally different followed by adding the elastomer to the system compared to neat epoxy resin. Moreover, the results obtained via our proposed facile solution blending method are compared to those of resins modified with nano-powdered elastomer.     

Simultaneous determination of adrenaline,uric acid,and cysteine using bifunctional electrocatalyst of ruthenium oxide nanoparticles

In this study, ruthenium oxide nanoparticles were electrochemically deposited on the surface of a glassy carbon electrode (RuON-GCE). Electrochemical studies indicate that a modified electrode (RuON-GCE) plays the role of an excellent bifunctional electrocatalyst for the oxidation of adrenaline (AD) and uric acid (UA) in two different potentials. The charge transfer coefficient (α) and the heterogeneous charge transfer rate constant (k′) between the analytes and the electrodeposited nanoparticles were determined using cyclic voltammetry experiments. Through a different pulse voltammetric (DPV) method, the plot of the electrocatalytic current versus AD and UA concentrations emerged to be constituted of two linear segments with different sensitivities. Furthermore, the detection limits of AD and UA were estimated. In DPV, RuON-GCE could separate the oxidation peak potentials of AD, UA, and cysteine (Cys) present in the same solution though, at the bare GCE, the peak potentials were indistinguishable. Finally, the modified electrode activity was studied for the electrocatalytic determination of AD in an injection solution and UA in a human urine sample. The results were found satisfactory.