Rhodium(III)‐Catalyzed in situ Oxidizing Directing Group‐ Assisted C?H Bond Activation and Olefination: A Route to 2‐Vinylanilines

A new and efficient method for the synthesis of 2‐vinylanilines from the reaction of arylhydrazine hydrochlorides with alkenes and diethyl ketone via a rhodium‐catalyzed C H activation is described. The oxidant‐free olefination reaction involves the in situ generation of an  N NCR¹R² moiety as the oxidizing directing group thus providing an easy access to 2‐vinylanilines.

     

Numerical inverse definite minimum time overcurrent relay for microgrid power system protection

Access of distributed generation gets complicated at the distribution level, and hence managing these systems effectively becomes highly challenging. Microgrids have been proposed as a way of integrating a large number of distributed renewable energy sources with a distribution system. They are low to medium voltage networks of small load clusters with distributed generation sources and storages. Microgrids can be operated in the islanded mode or the grid‐connected mode. If a microgrid is connected to the system, it is seen as a single aggregate load. One of the potential advantages of a microgrid is that it could provide more reliable supply to customers by islanding itself from the system in the event of a major disturbance. However, a major problem with microgrid implementation in islanded operation is designing a proper protection scheme. The fault currents for grid‐connected and islanded microgrids are significantly different. Additionally, high penetration of inverter‐connected distributed generation sources leads to conditions where no standard overcurrent protection method will work. Overcurrent protection is considered as the backbone of any protection strategy, especially in distribution systems. Distribution systems constitute the largest portion of the power system network, and therefore the diagnosis of faults in this system is a challenging task. Faults occurring in distribution systems will affect the reliability, security, and quality of a power system. Field‐processable gate array (FPGA) Xilinx Zynq‐based numerical overcurrent relay protection is provided to the microgrid that is operated in islanded mode. This results in faster discrimination and quicker isolation of the faulty section from the microgrid. This improves the reliability of the microgrid because the fault is rapidly diagnosed and isolated from the healthy part, thanks to the high‐speed operation of the 800‐MHz FPGA Xilinx Zynq‐based numerical overcurrent relay. This system is simulated using MATLAB Simulink SimPower system tool box and LabView software. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Cyber security in New Space

International Journal of Information Security - Developments in technologies, attitudes and investment are transforming the space environment, achieving greater accessibility for an increasing...     

A Review on Biogenic Synthesis of Selenium Nanoparticles and Its Biological Applications

In recent decades, aquaculture and environment plays a noteworthy role in rewarding the massive stipulate in all industries. Environmental damage and disease domination are seen as essential issues in the region. In addition to these, nanotechnology as a fresh and imaginative instruments were extremely feasible in aquaculture and environmental applications. Next-generation biological applications of these nanomaterials might lead to an explosion in the bio industries. In order to utilizing the nanoparticles of biogenic expansion, selenium has plays major role in the biological progresses. Selenium (Se) is a multifunctional trace element. The present review analytically intends to the potential biological applications of biosynthesized selenium nanoparticles (SeNPs). Synthesis of SeNPs physical, chemical and biological methods has been used. Physical and chemical methods of SeNPs have high cost, non ecofriendly, highly time consuming. Therefore, there is a growing concern to develop eco friendly and sustainable methods for biosynthesis. Biosynthesis method has ecofriendly, low cost, nontoxic and zero contamination. Biosynthesis of selenium nanoparticles by plant extracts, bacteria, protein, biopolymers, seaweed extracts, fungi and yeasts have used for capping or stabilizing agents. Therefore this review represented original evidence for antibacterial, antifungal, antibiofilm, antioxidant, anticancer, antidiabetic, antimosquito larvicidal and aquaculture applications of prospective biogenic SeNPs were provided in turn in this regard of literatures. Bio synthesis of SeNPs and it is used for many applications like medical, environmental and aquaculture applications. In this review study, the importance of selenium nanoparticles as a competitive element for sustainable aquaculture and environmental applications is also examined in detail.

     

Optimization of electric discharge machining using simulated annealing

This paper proposes an optimization methodology for the selection of best process parameters in electro-discharge machining. Regular cutting experiments are carried out on die-sinking machine under different conditions of process parameters. The system model is created using counter-propagation neural network using experimental data. This system model is employed to simultaneously maximize the material removal rate as well as minimize the surface roughness using simulated annealing scheme. Finally consistency of the method is tested with several initial trail values. Results are shown in the form of tables and figures.     

MODIFICATIONS OF BITUMEN BY ELASTOMER AND REACTIVE POLYMER—A COMPARATIVE STUDY

With increasing demand for higher performance, different modifications to asphalt are being explored. Asphalt is expected to become harder on modification thereby improving its life span. The modification further helps asphalt in developing resistance to cracking/fatigue at low temperatures and stability with minimum creep at higher temperatures. Polymers and rubber are being blended with asphalt to obtain good low temperature as well as high temperature performance. Various factors such as polymer chemical nature, molecular weight and particle size play a crucial role in determining the effect of modified asphalt properties. The effect of these factors and physical/chemical interaction between the additive and asphalt has not yet been fully established due to limitations in appropriate evaluation methodologies. This paper attempts to evaluate the improvements in modification of asphalt due to the addition of an elastomer and a reactive polymer, relatively. The evaluation is made more reliable and valid by considering all the three key characteristics namely cohesion, adhesion and durability aspects of the asphalt as the basis to highlight the improvements in application benefits.     

Prediction of surface roughness in turning operations by computer vision using neural network trained by differential evolution algorithm

In recent years, the measurement of surface roughness of a workpiece plays a vital role since the roughness of a surface has a considerable influence on the product quality and the functional aspects. In this work, a differential evolution algorithm (DEA)-based artificial neural network (ANN) has been used for the prediction of surface roughness in turning operations. Cutting speed, feed rate, depth of cut, and average gray level of the surface image of workpiece, acquired by computer vision, were taken as the input parameters and surface roughness as the output parameter. The results obtained from the DEA-based ANN model were compared with the backpropagation (BP)-based ANN. It is found that the error percentage is very close, and it is also observed that the convergence speed for the DEA-based ANN is higher than the BP-based ANN.     

Cloning and functional expression of Citrobacter amalonaticus Y19 carbon monoxide dehydrogenase in Escherichia coli

Carbon monoxide (CO) is highly toxic but is an abundant carbon source that can be utilized for the production of hydrogen (H₂). CO-dependent H₂ production is catalyzed by a unique enzyme complex composed of carbon monoxide dehydrogenase (CODH) and CO-dependent hydrogenase (CO–H₂ase), both of which contain metal cluster(s). In this study, CODH and the required maturation proteins from the novel facultative anaerobic bacterium Citrobacter amalonaticus Y19 were cloned and heterologously expressed in Escherichia coli. For functional expression of CODH in E. coli, only CooF (ferredoxin-like protein) and CooS (CODH), not the maturation proteins, were needed. The recombinant E. coli BL21(DE3)-cooFS showed a 3.5-fold higher specific CODH activity (4.9 U mg protein⁻¹) compared to C. amalonaticus Y19 (Y19) (1.4 U mg protein⁻¹). Purified heterologous CODH from the soluble cell-free extract of the recombinant E. coli showed a specific activity of 170.6 U mg protein⁻¹. Recombinant E. coli harboring Y19 CODH and maturation proteins did not produce H₂ from CO, suggesting that the native hydrogenases present in E. coli could not substitute the Y19 CO–H₂ase for CO-dependent H₂ production.     

Role of newspapers in creating mass concern with environmental issues in India

The present study has been undertaken with the objective of assessing the role of Indian newspapers in creating mass concern with environmental issues. The content analysis of three leading national English dailies revealed that these newspapers publish news items, editorials and articles on environmental issues of local, national and international interest. They brought into focus specific environmental problems in sufficient intensity with scope and time. A survey was conducted to obtain opinions of individuals about the extent of role of Indian newspapers in arousing popular interest by way of disseminating information about the environmental problems. The response strongly suggests a limited role of the Indian press in creating mass concern with environmental issues. Various reasons for the unsuccessful performance of the press have been presented. Two mass media‐public interaction models are also discussed in light of their value for the environmental problems of India.     

Quantitative method for analysis of monensin in soil, water, and urine by direct combination of single-drop microextraction with atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry

A simple and selective analytical method for the quantitative determination of low concentrations of monensin in soil, surface water, and human urine has been developed. Prior to atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) analysis, the samples were preconcentrated by using the single-drop microextraction (SDME) technique. Several factors that affect the analyte's extraction, including selection of solvent, microdrop volume, extraction time, and ionic strength, were investigated. Chloroform-toluene (1:1, v/v) was selected as the extraction solvent. Reliable results were obtained using dibenzo-30-crown-10-ether as an internal standard. The proposed method has been successfully applied for the determination of monensin in soil, surface water, and human urine spiked samples. Under the optimized conditions, the limits of quantification of the analyte in surface water, soil, and human urine were 6.7, 12.4 and 7.8 ng/mL, respectively. The intraday and interday precision variation and accuracy of the present method is within the acceptable ranges. The present method avoids the pre- and postderivatization of weak UV absorbing monensin determination using high performance liquid chromatography-ultraviolet detection (HPLC-UV). Furthermore, these techniques are time-consuming, nonreproducible at trace levels, and form undesirable products. The proposed SDME combined with AP-MALDI-MS is simple, fast, and selective for the determination of monensin in environmental and urine samples.