Synthesis,characterization and biological analysis of transition metal complexes with macro cyclic ligands derived from adipic acid,ethylenediamine with diethyloxalate and diethylmalonate

Macro-cyclic ligands from adipic acid, ethylenediamine with diethyloxalate and diethylmalonate and their respective metal complexes of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) with macro cyclic ligands (LO) and (LM) L [N,N′-bis(2-aminoethyl)hexanediamide] were synthesized successfully. These metal complexes were characterized by Fourier transform infrared, ultraviolet visible spectrometry, proton nuclear magnetic resonance spectroscopy, and mass Spectrometry, CHNS and thermogravimetric analysis. The elemental analysis confirms the structures for Mn(II), Co(II) and Ni(II) complexes similar to octahedral geometry, Cu(II) complexes as a square planar geometry and Zn(II) complexes in the tetrahedral geometry. The molar conductivities of all the metal complexes were taken in 10^?3 M DMSO, and values of all the metal complexes showed their electrolytic nature which indicates the presence of chloride ions. Thermal analysis supports as the metal complexes are thermally stable. The result of antimicrobial activity against various microorganisms confirms that the metal complexes are potent bactericides and fungicides than the ligand. Metal complexes of LO with Cu(II) and Zn(II) were found to be highly active against S. typhimurium than the complexes of LM.

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MC-MAC: a multi-channel based MAC scheme for interference mitigation in WBANs

Wireless body area networks (WBANs) support the inter-operability of biomedical sensors and medical institutions with convenience and high-efficiency, which makes it an appropriate solution for the pervasive healthcare. Typically, WBANs comprise in-body or around-body sensor nodes for collecting data of physiological feature. Therefore, the efficient medium access control (MAC) protocol is a crucial paramount to coordinate these devices and forward data to the medical center in an efficient and reliable way. However, the extensive use of wireless channel and coexistence of WBANs may result in inevitable interference which will cause performance degradation. Besides, contention-based access in single channel in WBANs is less efficient for dense medical traffic on account of large packet delay, energy consumption and low priority starvation. To address these issues above, we propose a multi-channel MAC (MC-MAC) scheme to obtain better network performance. Considering the characteristic and emergency degree of medical traffic, we introduce a novel channel mapping and selection mechanism, cooperating with conflict avoidance strategy, to organize nodes to access available channels without collisions. In addition, we have evaluated the performance of MC-MAC and the standard IEEE 802.15.6 via simulation and hardware test. The test is conducted by hardware platform based on prototype system of WBANs. Both of the analysis and simulation results show that MC-MAC outperforms the IEEE 802.15.6 in terms of packet delay, throughput, packet error rate and frame error rate.     

An Improved Energy Efficient Clustering Protocol for Increasing the Life Time of Wireless Sensor Networks

The intention behind this article is to devise a fresh clustering algorithm for Wireless Sensor Networks. The major aspiration is to curtail the energy utilization at the cluster building and data transmission levels to the Base Station. The algorithms offered are not dedicated to a particular type of sensor network or a specific application. We consider several parameters when choosing Cluster Head such as energy, degree and distance. These parameters have been studied separately or in combination in several literature works and their efficiency in terms of energy utilization and structural stability have been shown. The proposed approach is termed as the Distance Energy Evaluated (DEE) Approach. The DEE approach has lower intricacy in message size. The proposed approach is tested by running various MATLAB simulations. The results illustrate that our proposed protocol has shown significant improvement as compared to other approaches in terms of the lifespan of the network and energy usage.

     

MIMO-Frequency Diverse Array Radar with Unequal Subarrays for Improved Range-Angle Dependent Beamforming

Frequency diverse array (FDA) radar has been proposed in last decade for joint range and angle beamforming of a target. Multiple input multiple output-frequency diverse array (MIMO-FDA) radar has also been presented recently in literature to steer multiple beams by creating subarrays in transmit array. These beams help to localize the target in range as well as angle dimension. Due to same subarray size, all the beams have same beamwidth and thus exhibit same response for a given target. In this paper, we have proposed an unequal size subarrays structure for the FDA radar (US-MIMO-FDA), which allow us more focusing of the target in range and angle dimension by using beams of variable width. As a result the echoes received at the receiver help in better estimation of target parameters. The effectiveness of proposed scheme has been shown by comparing transmit and received beam patterns of proposed scheme with MIMO-FDA with equal subarrays Performance analysis of proposed scheme has also been done in terms of output signal to interference plus noise ratio, detection probability and cramer-rao lower bound. Simulation and results have verified better focusing of target by proposed design as compared to existing subarrays schemes for MIMO-FDA.     

Estimation of Residual Nickel and Some Heavy Metals in Vanaspati Ghee

To convert vegetable edible oils into vanaspati ghee, nickel is used as a catalyst in the hydrogenation process. A simple and fast method for the trace level determination of nickel in ghee is reported. In this work different methods were applied for the extraction of residual nickel from ghee samples. Using toluene, benzene and carbon tetrachloride as organic solvents, an acid mixture was used for the extraction of nickel. Extracted nickel was quantified with atomic absorption and colorimetric methods. Among the organic solvents, toluene proved to be the best solvent mediating a 95% extraction of nickel from ghee samples. Nickel was extracted and determined in ten different brands of ghee and in all samples its amount was well above the permissible limit of WHO (0.2 μg/g). Other metals like lead, zinc, copper, and cadmium were also determined and their concentrations were found to be much below the WHO permissible limits.     

Ensemble average of an arbitrary number of pairs of different eigenvalues using Grassmann integration

An identity satisfied by the eigenvalues of a real-symmetric matrix and an integral representation of a determinant using Grassmann variables are used to show that the ensemble average ofS different pairs of eigenvalues of a GOE is given by (–1) ^S 2^{–S –1/2}(S+1/2).     

Spectrophotometric Determination of Prochlorperazine Maleate in Pure and Pharmaceutical Preparations

 Prochlorperazine maleate reacts with 1-naphthylamine and sodium nitrite, after heating for 110 s at 80 °C to give an orange red colour having maximum absorbance at 460 nm. The reaction is selective for prochlorperazine maleate with 0.01 mg/mL as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.01 mg/10 mL to 0.33 mg/10 mL of prochlorperazine maleate and the relative standard deviation is 0.68%. The quantitative assessment of tolerable amounts of other drugs is also studied. Received September 22, 2000. Revision June 19, 2001     

2020 Roadmap on gas-involved photo-and electro-catalysis

In this roadmap, we address the development and perspectives of hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction and nitrogen reduction.     

Indirect Atomic Absorption Determination of Cocaine via Formation and Liquid‐liquid Extraction of the Iron(III)‐cocaine Complex

The principles of metal‐alkaloid ion‐pair formation and liquid‐liquid extraction are applied to the development of a sensitive and convenient atomic absorption spectrophotometery (AAS) method for the indirect determination of cocaine. In an aqueous medium of 5 M hydrochloric acid, cocaine is protonated and is associated with tetrachloro ferrate (III) anion prior to its extraction into 1,2‐dichloroethane. The critical experimental variables were identified and optimized. The method is simple and reproducible with a detection limit (DL) of 0.1 ng cm^?3 cocaine in water, a relative standard deviation of 0.07 (n = 12), and the calibration graph was linear up to 50 ng cm^?3 cocaine.