Novel synthesis of cerium oxide nano photocatalyst by a hydrothermal method

Crystalline cubic cerium oxide nano particles have been synthesized from cerium (Ⅲ) nitrate (Ce (NO3)3.6H2O) and sodi-um hydroxide by a hydrothermal method.The effect of three different molar ratios of the NaOH precipitating agent on structur-al,optical,and photo catalytic activity was investigated.The synthesized cerium oxide nano particles were characterized by X-ray diffraction (XRD),a UV-vis spectrometer,scanning electron microscope (SEM),energy-dispersive X-ray spectroscopy (EDAX),Raman spectroscopy and X-ray photo electron spectroscopy (XPS).According to the findings,hydrothermally synthesized ceri-um oxide NPs have a high efficiency for photocatalytic degradation of methylene blue when exposed to UV light.Environment-al water pollution is the major issue of the atmosphere.To get fresh water,humans could search the resources to purify the wa-ter in simple way and degradation is the one of the methods to purify salt water.     

Synthesis and characterizations of nano-sized Ni(OH)2 and Ni(OH)2/poly(vinyl alcohol) nano composite

Nano-sized Ni(OH)₂ was synthesized by a co-precipitation method. Peaks between 500 and 750 cm⁻¹ in Fourier transform infrared spectroscopy (FTIR) confirmed the presence of metal hydroxide stretching. Thermo gravimetric analysis inferred that 69 wt% residue remained above 750 °C. High-resolution transmission electron microscopy analysis of Ni(OH)₂ revealed its size ranged from 80 to 110 nm with smooth morphology. Scanning electron microscopy inferred that pure Ni(OH)₂ has nano rod-like morphology and higher weight percentage of aniline-intercalated Ni(OH)₂ has agglomerated structure. UV–Vis spectrum detected the presence of Ni²⁺ ions at 210 nm and the existence of amino group in the basal spacing of Ni(OH)₂ was not clearly appeared in the spectrum. Photoluminescence (PL) inferred that aniline-intercalated Ni(OH)₂ showed higher PL intensity than the pristine poly(vinyl alcohol) its and nano composite.     

A study on the grinding of glass using electrolytic in-process dressing

Grinding of brittle materials such as glass is gaining importance due to the rapid developments in the areas of machining of storage devices, microlenses, and optical communication devices. Grinding of such glasses is difficult because grinding wheels wear out easily due to the hard and brittle nature of the materials being machined. Grinding wheels with fine abrasive size are required in order to achieve ductile mode grinding. Problems such as wheel loading and glazing can be encountered while grinding with fine abrasive wheels. Electrolytic in-process dressing (ELID) is an efficient method to dress the grinding wheel while performing grinding. In this paper, a fundamental study on the mechanism of the ELID grinding technique is discussed in detail. Several sets of experiments have been performed to determine the optimal grinding conditions. From the experiments, it has been established that surface roughness could be further improved if the current duty ratio to dress the grinding wheel were increased. The force patterns and the changes in the profile of the grinding wheel during machining are also presented and discussed in detail.     

Wear analysis of electrolytically dressed wheels for finishing substrate materials

Finishing of silicon wafers is a billion dollar global business. The present process chain consists of several processes, which lead to long production times and increase the cost of the finished materials. In the recent years, several processes have been experimented as an alternate process for finishing substrate wafers with stringent specifications. However, there are no successful alternate processes, which have been adopted by the wafer processing industries. The electrolytic in-process dressing (ELID) grinding is one of the processes that has already been experimented on silicon wafers for producing mirror surface finish. However, the flatness achieved from the ELID grinding is not reported. The main influence on the flatness of the wafers during ELID grinding may be due to the wear of the grinding wheels. The wear mechanism of electrolytically dressed wheels has not been fully understood and reported. The main objective of this study is to report the wear behaviors of the wheels during thinning and fine finishing of substrate wafers. The experimental results provide the conditions for utilization of the non-linear behavior of the electrolytically dressed grinding wheels for thinning and fine finishing processes.     

Wet oxidation of acid brown dye by hydrogen peroxide using heterogeneous catalyst Mn-salen-Y zeolite: a potential catalyst

Catalytic wet hydrogen peroxide oxidation of acid dye has been explored in this study. Manganese(III) complex of N,N'-ethylene bis(salicylidene-aminato) (salenH(2)) has been encapsulated in super cages of zeolite-Y by flexible ligand method. The catalyst has been characterized by FT-IR, XRD, TG/DTA and nitrogen adsorption studies. The effects of various parameters such as pH, catalyst and hydrogen peroxide concentration on the oxidation of dye were studied. The results indicate that after 20 min at 30 degrees C, 0.175 M H(2)O(2) and 3g/L catalyst, about 90% dye removal was obtained. These studies indicate that manganese-salen complex immobilized on zeolite framework can act as a good heterogeneous catalyst for removal of dye from wastewaters.     

Antibacterial and anticancer activity of biosynthesised CuO nanoparticles

The present investigation aims for the synthesis of copper oxide nanoparticles (CuO NPs) using Nilgirianthus ciliatus plant extract. The obtained CuO NPs were characterised by X‐ray diffraction, Fourier transform infrared spectrum, ultraviolet–visible spectroscopy, photoluminescence, scanning electron microscopy and transmission electron microscopy analysis. Significant bacterial activity was manifested by CuO nanoparticles against both Gram‐positive (Staphylococcus aureus and Staphylococcus mutans) and Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The synthesised CuO NPs have good cytotoxicity against both human breast cancer cell line (MCF‐7) and lung cancer cell line (A549) with minimum cytotoxic effect on normal L929 (fibroblast) cell lines.Inspec keywords: microorganisms, ultraviolet spectra, nanomedicine, transmission electron microscopy, visible spectra, cellular biophysics, antibacterial activity, nanoparticles, X‐ray diffraction, lung, copper compounds, cancer, toxicology, biomedical materials, scanning electron microscopy, photoluminescence, Fourier transform infrared spectraOther keywords: antibacterial activity, anticancer activity, biosynthesised CuO nanoparticles, copper oxide nanoparticles, Nilgirianthus ciliatus plant, X‐ray diffraction, infrared spectrum, ultraviolet–visible spectroscopy, transmission electron microscopy analysis, bacterial activity, Gram‐negative bacteria, synthesised CuO NPs, human breast cancer cell line, Staphylococcus aureus, Staphylococcus mutans, CuO     

Emotion enhanced retention of cognitive skill learning.

Ample evidence suggests that emotional arousal enhances declarative/episodic memory. By contrast, there is little evidence that emotional enhancement of memory (EEM) extends to procedural skill based memory. We examined remote EEM (1.5-month delay) for cognitive skill learning using the weather prediction (WP) probabilistic classification task. Participants viewed interleaved emotionally arousing or neutral pictures during WP acquisition. Arousal retarded initial WP acquisition. While participants in the neutral condition showed substantial forgetting of WP learning across the 1.5-month delay interval, the arousal condition showed no evidence of forgetting across the same time period. Thus, arousal during encoding determined the mnemonic fate of cognitive skill learning. Emotional enhancement of WP retention was independent of verbally stated knowledge of WP learning and EEM for the picture contexts in which learning took place. These results reveal a novel demonstration of EEM for cognitive skill learning, and suggest that emotional arousal may in parallel enhance the neural systems that support procedural learning and its declarative context. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An efficient cardiac signal enhancement using time–frequency realization of leaky adaptive noise cancelers for remote health monitoring systems

Nowadays telecardiology is an important tool in cardiac diagnosis from a remote location. During Electrocardiogram (ECG) or Cardiac Signal acquisition several artifacts strongly affect the ST segment, degrade the signal quality, frequency resolution, produce large amplitude signals in ECG that can resemble PQRST waveforms and mask the tiny features that are important for clinical monitoring and diagnosis. So the extraction of high-resolution cardiac signals from recordings contaminated with artifacts is an important issue to investigate. In this paper, various novel block based time–frequency domain adaptive filter structures for cardiac signal enhancement are presented. These filters estimate the deterministic components of the cardiac signal and remove the noise component. The Block Leaky Least Mean Square (BLLMS) algorithm, being the solution of the steepest descent strategy for minimizing the mean squared error in a complete signal occurrence, is shown to be steady-state unbiased and with a lower variance than the LMS algorithm. To improve the filtering capability some variants of BLLMS, Block Normalized LLMS (BNLLMS) and Block Error Normalized LLMS (BENLLMS) algorithms are implemented in both time domain (TD) and frequency domains (FD). Finally, we have applied these algorithms on real cardiac signals obtained from the MIT-BIH data base and compared their performance with the conventional LLMS algorithm. The results show that the performance of the block based algorithms is superior to the LLMS counterparts in terms of signal to noise ratio improvement (SNRI), excess mean square error (EMSE) and misadjustment (M). Among all the algorithms FDBENLLMS achieves higher SNRI than other techniques. These values are 25.8713 dB, 20.1548 dB, 21.6718 dB and 20.7131 dBs for power line interference (PLI), baseline wander (BW), muscle artifacts (MA) and electrode motion artifacts (EM) removal.     

Modified Reynolds Equation for Different Types of Finite Plates with the Combined Effect of MHD and Couple Stresses

We make an effort to analyze the behavior of squeeze film characteristics of different finite plates with couple stress fluid in the presence of a transverse magnetic field. On the basis of the Stokes couple stress fluid model and hydromagnetic flow model, a modified Reynold's equation is derived, which is solved by using appropriate boundary conditions to obtain squeeze film pressure, load-carrying capacity, and squeeze film time. The graphical representation of the results suggests that the different bearing systems register an enhanced performance with couple stresses compared to that of a bearing system working with a conventional lubricant in the presence of a transverse magnetic field. It is observed that the effect of applied magnetic field on the squeeze film lubrication between different finite plates with conducting couple stress fluids is to increase the load-carrying capacity significantly and to delay the time of approach compared to the corresponding nonconducting Newtonian case. It is seen that for all of the finite plates of different shapes, the circular shape gives the maximum load and time.