Synthesis of a Series of Hydroxycarboxylic Acids as Standards for Oxidation of Nonanoic Acid

The synthesis of a series of nonanoic acids hydroxylated in terminal,ω-1,ω-2,ω-3 positions is described. These compounds will be employed as useful standards for the study of enzymatic and microbiological oxidation of nonanoic acid.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Adsorption Isotherm,Kinetic, Thermodynamic,and Desorption Studies of Lanthanum and Dysprosium on Oxidized Multiwalled Carbon Nanotubes

The adsorption behavior of La(III) and Dy(III) onto multiwalled carbon nanotubes oxidized (MWCNTs-oxidized) with concentrate nitric acid as a function of pH and adsorbent dosage was studied by batch technique. Maximum adsorption uptakes, according to the Langmuir model were obtained as 99.01 mg/g for La(III) and 78.12 mg/g for Dy(III). The results showed that adsorption process of both metals ions followed well the pseudo-second-order kinetics. The results of Thermodynamic parameters showed that the adsorption of La(III) and Dy(III) onto MWCNTs-oxidized is a feasible, spontaneous, and exothermic process. The results of desorption indicated that most of the adsorbed La(III) and Dy(III) can be easily desorbed from MWCNTs-oxidized at low pH values.     

Inhibition of Scale Formation Using Silica Nanoparticle

Because of the wide use of water injection for enhanced oil recovery in the oil fields in order to displace oil into the production well, many reservoirs experience scale deposition problems. Scale formation can cause the production path to be blocked and also cause significant reduction in productivity. One of the most common methods for preventing or lowering the amount of scale formation is applying the scale inhibitors. In this work, silica nanoparticles are used as a scale inhibitor. Conductivity is used as a property of the fluid to show the amount of ion in the solution, leading us to predict the amount of scale formed in the solution. An optimum amount of silica nanoparticles could reduce the rate of conductivity decreasing the solution and consequently lowering the scale deposition, which is the aim of this challenging subject in the oil industry.     

A Comprehensive Review on Different Numerical Approaches for Simulation in Nanofluids: Traditional and Novel Techniques

Computational fluid dynamics (CFD) has already proven to be an important tool to study fluids flow characteristics. Due to the rapid growth of powerful computers, CFD has become more applicable nowadays. In the field of nanofluids, this tool has also been applied by different approaches to understand and explain the effective phenomena. This article reviews and summarizes the numerical investigations implemented on nanofluids including conventional and novel methods. The studies conducted using methods such as Lattice Boltzmann, Eulerian–Lagrangian, thermal dispersion, Eulerian–Eulerian, and so forth are assessed.     

The sol-gel derived Co-Mn/TiO_2 catalysts for light olefins production

In this research work,two 30%(Co-Mn)/TiO2catalysts were prepared using sol-gel(catalyst A)and coprecipitation(catalyst B)methods.The activity and selectivity to C2~4light olefins in Fischer-Tropsch synthesis(FTS)has been studied in a fixed-bed reactor under different operational conditions.These operational conditions were:temperature220~280℃,and total pressure from0.1~0.6 MPa.The optimum operating conditions were investigated after steady state.As the results shown,the catalyst A was more selective to C2~4olefins(58.7%in 260℃)and catalyst B was more selective to C5+hydrocarbons.Characterization of both catalysts was carried out by using X-ray diffraction(XRD),scanning electron microscopy(SEM)and N2adsorption-desorption measurements methods.     

以方沸石负载Ni(II)催化剂修饰的电极电氧化甲醇Seyed Naser Azizi,Shahram Ghasemi,Neda Salek Gilani简

There is a high overvoltage in the oxidation of methanol in fuel cells, and so modified electrodes are used to decrease it. A modified electrode that used Ni(Ⅱ) loaded analcime zeolite to catalyze the electrooxidation of methanol in alkaline solution was proposed. Analcime zeolite was synthesized by hydrothermal synthesis, and Ni(Ⅱ) ions were incorporated into the analcime structure, which was then mixed with carbon paste to prepare modified electrode. The electrocatalytic oxidation of methanol on the surface of the modified electrode in alkaline solution was investigated by cyclic voltammetry and chronoamperometry. The effects of the scan rate of the potential, concentration of methanol, and amount of zeolite were investigated. The rate constant for the catalytic reaction of methanol was 6×10³ cm³ mol^-1 s^-1 from measurements using chronoamperometry. The proposed electrode significantly improved the electron transfer rate and decreased the overpotential for methanol oxidation.     

Synthesis and Crystal Structure of N-（2-（1,3,4-oxadiazol-2-yl）phenyl）-2,3-dimethylaniline

The title compound, N-（2-（1,3,4-oxadiazol-2-yl）phenyl）-2,3-dimethylaniline, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, ^1H- and ^13C-NMR spectroscopy, elemental analysis and mass spectrometry. These experimental studies were supported by theoretical optimizations.     

Electropolymerized coatings of polyaniline on copper by using the galvanostatic method and their corrosion protection performance in HCl medium

The synthesis of polyaniline coatings on the copper (Cu) surface has been investigated by using the galvanostatic method. The synthesized coatings were characterized by Fourier transform infrared spectroscopy, UV–visible absorption spectrometry and scanning electron microscopy. The anticorrosion performances of polyaniline coatings were investigated in 0.5 M HCl medium by the potentiodynamic polarization technique and electrochemical impedance spectroscopy. The corrosion rate of polyaniline‐coated Cu was found to be ～27 times lower than bare Cu, and potential corrosion increased from ?0.21 V versus Ag/AgCl for uncoated Cu to ?0.19 V versus Ag/AgCl for polyaniline‐coated Cu electrodes. Electrochemical measurements indicate that polyaniline coating has good inhibiting properties with a mean efficiency of ~96% at 10 mAcm^?2 current density applied on Cu corrosion in acid media. The results of this study clearly ascertain that the polyaniline has an outstanding potential to protect Cu against corrosion in an acidic environment. Copyright © 2014 John Wiley & Sons, Ltd.     

Flutter control and mitigation of limit cycle oscillations in aircraft wings using distributed vibration absorbers

Nonlinear Dynamics - In this work, we demonstrate the application of the conserved-mass metamaterial concept to control the flutter onset in aircraft wings and mitigate their induced vibrations....