Showing papers by "Bishop Heber College published in 2016"
TL;DR: In this article, the antibacterial activity of nanosized TiO2 and Ba doped nanoparticles synthesized by a microwave assisted method was investigated by X-ray diffraction and scanning electron microscopy.
Abstract: In this work, we investigated the antibacterial activity of TiO2 and Ba doped TiO2 nanoparticles synthesised by a microwave assisted method. The obtained nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, ultra-violet visible spectroscopy, energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy. XRD patterns revealed preferentially oriented (101) TiO2 anatase phase, which changed to anatase–rutile mixed phase after Ba2+ doping. The vibrational spectra show significant shifts in the peaks with Ba addition, indicating the successful incorporation of Ba2+ ions into TiO2. The optical spectra revealed increase in band gap with Ba doping, thereby allowing the delay in recombination rate, favouring antibacterial activity. The surface morphology of TiO2 show spherical shaped grains with increased porosity after Ba doping. EDS analysis confirmed the phase-purity of the synthesized powders. The potential toxicity of nanosized TiO2 and Ba doped TiO2 were investigated using both Gram positive and Gram negative bacteria as test organisms. The antibacterial activity was found to be higher for Ba doped TiO2 nanoparticles compared to pure TiO2 nanoparticles, due to reduced particle size and high specific surface area leading to enhanced particle surface reactivity to light and H2O adsorption.
59 citations
TL;DR: The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.
Abstract: Production of antimicrobial agents through the synthesis of gold nanoparticles using green technology has been extensively made consistent by various researchers; yet, this study uses the flower bud’s aqueous extracts of Brassica oleracea (Broccoli) as a reducing agent for chloroauric acid (1 mM). After 30 min of incubation, synthesis of gold nanoparticles (AuNps) was observed by a change in extract color from pale yellow to purple color. Synthesis of AuNps was confirmed in UV–visible spectroscopy at the range of approximately 560 nm. The SEM analysis showed the average nanoparticles size of 12–22 nm. The antimicrobial activity of AuNps was analyzed by subjecting it to human pathogenic bacteria (Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumonia) and fungi (Aspergillus flavus, Aspergillus niger and Candida albicans) using disc diffusion method. The broccoli-synthesized AuNps showed the efficient antibacterial and antifungal activity of above-mentioned microbes. It was confirmed that AuNps have the best antimicrobial agent compared to the standard antibiotics (Gentamicin and Fluconazole). When the concentrations of AuNps were increased (10, 25, and 50 µg/ml), the sensitivity zone also increased for all the tested microbes. The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.
45 citations
TL;DR: Chitosan-silver nanoparticles synthesized showed substantial growth promotory effect on chickpea seed germination, seedling length, fresh and dry weight and a consequential increase in enzyme activity including α, β-amylase, ascorbate peroxidase and catalase was observed with nanoparticle treatment.
Abstract: Chitosan-silver (Ag-CS) nanoparticles were synthesized and their physico-chemical characterization was carried out by DLS, TEM and FTIR. The study highlighted the reduced size (20–50 nm)and mono-disperse nature of Ag-CS Nps. Experiments were carried out to study the efficacy of Ag-CS Nps on chickpea seeds. Laboratory synthesized nanoparticles (0.1%, w/v) showed substantial growth promotory effect on chickpea seed germination, seedling length, fresh and dry weight. Regarding the pigment content, nanoparticles treated seedlings showed a remarkable increase of chlorophyll. A consequential increase in enzyme activity including α, β-amylase, ascorbate peroxidase (APX), peroxidase (POD) and catalase (CAT) was observed with nanoparticle treatment. In addition, Ag-CS Nps showed higher expression of MDA content. The overall results confirm the significant growth promotory effect as well as biochemical variation capabilities of Ag-CS Nps. This study opens up the possibility to use Ag-CS Nps as growth promotors in chickpea under the pot and field condition with the knowledge of toxicity levels.
42 citations
TL;DR: By adding fluorine, an anionic co-dopant with antimony, a cationic dopant, Sb+F doped ZnO films are prepared using a simplified spray technique and the effect of fluorine concentration (0, 5, 10 and 15 at%) on electrical, optical, structural and surface morphological properties are studied as discussed by the authors.
36 citations
TL;DR: In this article, a simple, low-cost and mass producible composite made up of cetyltrimethylammonium bromide (CTAB) functionalized polyaniline (PANI) and activated charcoal was proposed for simultaneous determination of dopamine (DA) and uric acid (UA).
Abstract: We describe a simple, low-cost and mass producible composite made up of cetyltrimethylammonium bromide (CTAB) functionalized polyaniline (PANI) and activated charcoal (CTAB–PANI/AC) for simultaneous determination of dopamine (DA) and uric acid (UA). The composite formation was verified through scanning electron microscopy, electrochemical impedance spectroscopy and electrochemical methods. The CTAB–PANI/AC composite was used to modify a glassy carbon electrode (GCE) and the resulting modified electrode displayed excellent electrocatalytic activity to DA and UA and successfully separates their overlapped voltammetric peaks. The composite completely inhibits the AA signal and does not produce any voltammetric signal for AA up to 2 mM. The DA and UA can be selectively detectable up to detection limits of 0.06 (±0.006) μM and 0.20 (±0.008) μM, respectively. The effects of kinetics, analyte concentration and pH of the supporting electrolyte were investigated and optimized. The modified electrode has appreciable stability, repeatability and reproducibility. Besides, the practical feasibility of the sensor is demonstrated in biological samples, which delivered satisfactory recovery results.
32 citations
TL;DR: In this paper, the fabrication of a novel nano-whiskers array of Cr incorporated ZnO on ITO substrate exhibiting high sensing response to hydrogen (H 2 ) gas at room temperature was explored.
Abstract: This study explores the fabrication of a novel nano-whiskers array of Cr incorporated ZnO on ITO substrate exhibiting high sensing response to hydrogen (H 2 ) gas at room temperature. The Cr-ZnO films prepared by a novel spray deposition route were characterized for its structure, composition, optical and luminescence properties. The crystal structure revealed that the Cr dopants were well integrated into the ZnO wurtzite lattice. All the films exhibit single crystalline nature with high c-axis orientation. Cr dopant played an essential role in the enhancement of the crystalline quality and optical band gap energy of the films. The PL spectra revealed strong and broad violet-blue emission from Cr-ZnO nano-whiskers with increasing Cr content. SE-micrograph of the films show the remarkable change in morphology from nanotubes to nanowires with increase in Cr dopant concentration. The Cr dopant exhibit significant effect in fine tuning the structure of nanoparticles and size of the nano-whiskers. The H 2 gas sensing characteristics of Cr-ZnO nano-whiskers was investigated. Amongst all sensors fabricated with different Cr dopant concentration, the 4 at.% Cr incorporated ZnO sensor exhibited fast response and recovery towards low concentration of H 2 at room temperature.
31 citations
TL;DR: In this article, the dynamics of superposed nonlinear waves in coherently coupled Gross-Pitaevskii (CCGP) equations with constant and time varying nonlinearity coefficients are studied.
28 citations
TL;DR: In this paper, the electrochromic effect of cobalt oxide thin films was studied as a function of substrate temperature (573 −673 K), and Williamson-Hall analysis was made to understand the strain variation in the prepared Co3O4 films under different deposition temperature by employing uniform deformation model.
Abstract: Electrochromic effect of cobalt oxide thin films was studied as a function of substrate temperature (573–673 K). Tricobalt tetraoxide (Co3O4) thin films were deposited on glass and fluorine-doped tin oxide (FTO) substrates by nebulized spray technique using cobalt nitrate as precursor material. The XRD patterns indicated (311) plane was dominant for all the films irrespective of the deposition temperature. Williamson-Hall (W-H) analysis was made to understand the strain variation in the prepared Co3O4 films under different deposition temperature by employing uniform deformation model (UDM). Scanning electron microscopy images revealed porous morphology for the film prepared at 623 K. The optical parameters such as refractive index (n), extinction coefficient (k), and band gap were derived from UV-visible spectra of Co3O4 films. The electrochromic performance of the deposited Co3O4 films was analyzed through cyclic voltammetry, chronocoulometry, chronoamperometry, and iono-optical studies.
24 citations
TL;DR: In this paper, the authors report the room temperature ethanol sensitivity of pristine WO3 and Fe activated microspheres architecture prepared by a novel spray pyrolysis method, which exhibits single crystalline nature with preferentially oriented (200) plane along c-axis direction.
20 citations
TL;DR: A mechanism for tuning the speed by altering the nonparaxial parameter is proposed and a novel phase-unlocking behavior due to the presence of non paraxial parameters is identified.
20 citations
TL;DR: In this article, selective faceted growth of highly ordered TiO2 (002) nanorods were coated over fluorine doped tin oxide (FTO) substrate prepared by facile and cost effective hydrothermal method for different reaction temperatures (100, 120, 140, and 160 °C).
Abstract: Selective faceted growth of highly ordered TiO2 (002) nanorods were coated over fluorine doped tin oxide (FTO) substrate prepared by facile and cost effective hydrothermal method for different reaction temperatures (100, 120, 140 and 160 °C). The rutile phase TiO2 and highly preferential oriented along (002) plane were confirmed from the XRD pattern. The TiO2 thin film, prepared with different reaction temperature consisting of anisotropic structures was analysed by SEM and the elemental composition of the films was identified using EDAX. The optical band gap of the TiO2 thin films was found to be 3.5–3.1 eV using UV–visible spectroscopy. The presence of rutile TiO2 phase was confirmed from raman analysis. As a result of photoluminescence studies, improvement of charge separation with low recombination rate was observed in TiO2 thin films. The anionic (Congo Red, Direct Red) and cationic (Rhodamine B and Malachite Green) dye decolorisation of the TiO2 thin films was investigated under visible light from photocatalytic activity.
TL;DR: In this article, molybdenum doped zinc oxide (MZO) thin films were deposited onto glass substrates by sol-gel spin coating method and the optical studies showed that all the films are highly transparent in the visible region (~85%).
TL;DR: This type of realization of logic gates just from a three soliton collision (pair-wise interaction) is clearly distinct from the earlier studies which require separate collisions of four solitons.
TL;DR: The present study confirmed that the presence of active compounds in different parts of B. acuminata is confirmed and the isolation of above mentioned bioactive compounds from the different part of the plant would be useful to find out the novel drugs.
Abstract: Barleria acuminata Nees (Acanthaceae) commonly known as Vellaikurunji. It is used as one of the most important drugs in traditional system of medicine. The GC-MS analyses showed that the presence of Twenty two different phytocompounds in ethanolic extract of leaf of B. acuminata . The highest peak area of 34.13% for 9,12,15-Octadecatrienoic acid,(z,z,z)- was identified in leaf of B. acuminata . The ethanolic stem extract of B. acuminata showed that the presence of Twenty six different phytocompounds. The highest peak area of 46.73% for Piperidine,2,2,6,6-tetramethyl-. The root extract of B. acuminata showed that the presence of Twenty four different bioactive compounds. The root of B. acuminata showed Piperidine,2,2,6,6-tetramethyl- with the highest peak area of 39.58%. The present study confirmed that the presence of active compounds in different parts of B. acuminata. In future, the isolation of above mentioned bioactive compounds from the different part of B. acuminata would be useful to find out the novel drugs.
TL;DR: In this paper, a single crystal EDA(2,4-dinitrophenolate) was grown by solvent evaporation method for optical limiting applications against intense ultrashot pulse lasers.
TL;DR: In this paper, the impact of drought stress factor on in vitro antioxidant potential of chloroform insoluble fraction (phenolics) of leaves and flowers extract of Tridax procumbens was investigated.
TL;DR: The synergetic electrocatalytic effect of the CNT/Ta electrode with excellent redox chemistry is promising for the development of highly sensitive biosensors.
Abstract: In the present study, the properties of functionalized multiwalled carbon nanotube thin films deposited on Ta and Al2O3 substrates were compared for better electrochemical sensing performance towards H2O2. We pioneer the fabrication of high quality carbon nanotubes by electron beam evaporation at a high vacuum of 10−6 mTorr. The fabricated films were further characterised using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and cyclic voltammetry (CV). Crystallographic properties revealed that the carbon nanotube (CNT) film grown on the Al2O3 substrate exhibits a preferentially oriented (002) peak with high intensity compared to that on Ta. CNTs fabricated on a Ta substrate show better morphology with tightly packed grains and decreased nanotube diameter than the film on sapphire. TEM images confirmed the well adherent and dense nature of the nanotubes on Ta. Electrochemical H2O2 sensors were constructed to demonstrate the sensing performance of CNT/Ta and CNT/sapphire electrodes. CV curves of the samples show high sensitivity for the MWCNT film grown on Ta due to the highly conductive acid resisting nature of the substrate, overcoming the obstacles to electrochemical H2O2 sensing. Compared with the CNT/sapphire electrode, the CNT/Ta electrode exhibited high electrocatalytic activity towards the oxidation of H2O2, as distinct nanotubes are electrochemically linked with the conductive Ta substrate. The CNTs on Ta revealed a very low detection limit of 0.07 μm due to the nanoporous morphology of the film which supported better penetration of electrolytes into the electrode material. The synergetic electrocatalytic effect of the CNT/Ta electrode with excellent redox chemistry is promising for the development of highly sensitive biosensors.
TL;DR: In this paper, a photoelectron spectrometer was used to detect the presence of Cu, Mn and O in the nanostructures of the ABO2 group of compounds, and the ethanol gas sensing property of the CuMnO2 films were measured at RT, 100 and 200 °C temperatures.
Abstract: Copper manganese oxide nanostructures were spray pyrolytically deposited on glass substrates with Cu:Mn concentrations 0.05:0.05, 0.1:0.1, 0.15:0.15, 0.2:0.2 M at the substrate temperature of 300 °C. The peak positions of the films deposited with precursor concentration 0.15:0.15 M confirmed the monoclinic CuMnO2 single phase structure. Surface morphology of the films was analyzed and then the chemical environment about the presence of Cu, Mn and O was analyzed in a photoelectron spectrometer. The binding energies of Cu-2p doublet positioned at 932.5 and 952 eV, represented the existence of Cu1+ in the films. Additional peak located at binding energies 638.8 and 650.3 eV corresponds to the Mn-2p of the film. The direct band gaps of the film were estimated and found near to 3.7 eV. The room temperature electrical conductivity of the film was 0.5577 mho/cm, which was comparatively high in the ABO2 group of compounds. The ethanol gas sensing property of the CuMnO2 films were measured at RT, 100 and 200 °C temperatures and the sensitivity was analysed and compared.
TL;DR: A promising electrode material barium manganate (BaMnO3) for electrochemical supercapacitor was prepared by solution combusted manganese tartrate complex process as discussed by the authors.
TL;DR: The experimental study with enhanced k Nearest Neighbor method shows better and promising classification result for classifying benign and malignant tissues.
Abstract: Objectives: To detect and classify the malignant cancer tissues and benign cancer tissues in MR lung cancer images by using k nearest neighbor mining algorithm. Methods/Statistical Analysis: In this paper, the Enhanced K Nearest Neighbor (EKNN) algorithm is executed to identify the lung cancer images. The k nearest neighbor technique is an important method of data mining algorithms. Findings: This work implicates four stages such as pre-processing, feature extraction, classification and detection of cancer tissues. In preprocessing stage, morphological process is used to filter the irrelevant noisy data in images. In the second phase, statistical and discriminator algorithm is used to extract the images. In the last stage, the improved k Nearest Neighbor (EKNN) method has been used to classify and identify the cancerous tissues in MRI images. The detection of cancer tissues and classification is done by executing four steps of Enhanced k Nearest Neighbor method which are measuring the Euclidean distance value, determining the k value, calculating the minimum distance and detecting the cancerous cells. Improvements/Applications: The experimental study with enhanced k nearest neighbor method shows better and promising classification result for classifying benign and malignant tissues.
TL;DR: In this paper, the sintering time of solid-state reaction of CuNb2O6 with various microstructures was investigated and a rod structure due to densification and coalescence process was observed.
01 Jul 2016
TL;DR: A model is proposed to solve MAGDM problems using the developed distance formula defined for ITrFNs and comparisons are made with some of the existing MAGDM models and ranking procedures.
Abstract: Solving Multiple Attribute Group Decision Making MAGDM problems has become one of the most important researches in recent days. In situations where the information or the data is of the form of an Intuitionistic Triangular Fuzzy Number ITrFN or Intuitionistic Trapezoidal Fuzzy Number ITzFN, a new distance function is defined for ranking the alternatives in the decision making process. After processing the decision information through a sequence of arithmetic aggregation operators, namely, the Intuitionistic Triangular Fuzzy Weighted Arithmetic Averaging ITrFWAA, Intuitionistic Triangular Fuzzy Ordered Weighted Averaging ITrFOWA operator and the Intuitionistic Triangular Fuzzy Hybrid Aggregation ITrFHA operator, the proposed distance function is utilized to rank the best alternative. A model is proposed to solve MAGDM problems using the developed distance formula defined for ITrFNs. Numerical illustration is provided and comparisons are made with some of the existing MAGDM models and ranking procedures.
TL;DR: In this paper, a dielectric portrayal study on relaxation and molecular interaction of in ternary blend of polymer and the surfactant viz. polyvinyl alcohol (PVA) and sodium dodecyl sulphate (SDS) in aqueous solutions focused on various concentrations at 298 K.
TL;DR: Biosynthesis of the secondary metabolites of Tridax procumbens is not only controlled genetically, but also strongly influenced by the habitats, and the antioxidant potential of plant extracts derived from high altitude samples were higher than dry and wet-lands.
TL;DR: In this article, a triple layer system (TaZO/Ag/TaZoO) consisting of tantalum doped zinc oxide and metallic silver (Ag) was deposited onto glass substrates.
Abstract: A triple layer system (TaZO/Ag/TaZO), consisting of tantalum doped zinc oxide (TaZO) as the top and bottom layers and metallic silver (Ag) as the intermediate layer, was deposited onto glass substrates. The top and bottom layers were deposited using an inexpensive home-made automated jet nebulizer spray technique (AJNSP) and the intermediate Ag layer was deposited using a thermal evaporation technique. Three different sets of samples with top and bottom layers having thickness values of around 50, 75 and 100 nm, respectively, were prepared, keeping the thickness of the middle layer constant (15 nm). The influence of thickness on structural, electrical, optical and photoluminescence properties along with surface morphology of the deposited triple layer systems was studied. A structural study revealed that the deposited films have the hexagonal wurtzite structure of ZnO, and an X-ray photoelectron spectroscopic study confirmed the presence of the expected elements in the system. Optical studies showed that the overall thickness of the films influences only marginally the transmittance of the films. The decrease in sheet resistance with the increase in thickness is explained on the basis of a grain boundary scattering mechanism. Among all the films examined, the multilayer film with the 75 + 15 + 75 nm thickness exhibited the best quality factor (8.98 × 10−3 (Ω sq−1)−1), and may be considered as a potential candidate for transparent electrode applications. To the best of our knowledge, this is the first report in which a low-cost chemical technique has been employed to fabricate a triple layer system.
TL;DR: Clustering is a data mining technique widely used to find similar group of data that has most similar data while the elements from the different clusters are dissimilar, which aids to find more solutions in data mining domain.
Abstract: Clustering is a data mining technique widely used to find similar group of data. A better cluster always have most similar data while the elements from the different clusters are dissimilar. Genetic algorithms GAs are considered as a global searching technique for optimisation problems. In the recent years there are many conflicting measure of objectives which are need to be optimised concurrently to achieve a tradeoff. Traditionally, evolutionary algorithms EAs were used to solve single objective problems. Optimum performance in single objective optimisation often results low, when the situation deals with more than one objective. This situation creates a bottleneck for an alternate technique called as multi-objective optimisation using genetic algorithms which aids to find more solutions in data mining domain.
TL;DR: It is suggested that oestrus‐specific urinary pheromones have the potential to modulate the endocrine system and alleviate the male reproductive toxic effects produced by 3‐MC.
Abstract: Polyaromatic hydrocarbons (PAHs) are persistent organic pollutants that contribute to endocrine/gonadal disruption. This study was designed to investigate the endocrine modulating role of pheromones in alleviating the reproductive toxic effects of 3-MC (3-methylcholanthrene), one of the common PAHs, in rat model. The rats were injected intraperitoneally with 3-MC at a dose of 25 mg kg(-1) BW. The serum levels of testosterone and other biochemical parameters were altered to significant levels in 3-MC-treated rats and oestrus-specific urine exposure restored all these effects to near normal. Although testis weight did not indicate any significant change, sperm and spermatid counts were significantly reduced in 3-MC-treated rats, which became normal in oestrus-urine-exposed rats. Hence, this study suggests that oestrus-specific urinary pheromones have the potential to modulate the endocrine system and alleviate the male reproductive toxic effects produced by 3-MC.
TL;DR: The pharmacological activity of the ligand and the complexes was investigated by antioxidant, antimicrobial and cytotoxic activity, and they show promising pharmacological effect.
Abstract: Synthesis of new metallic complex of cobalt and zinc with amino acid-nucleobase hybrid ligand have been achieved by simple chemical reaction of metal salt with amino acid L-histidine and nucleobase adenine as ligands. Various physicochemical techniques such as elemental analysis, conductometric measurements, FT-IR, UV-visible, (1)H & (13)C NMR, mass spectroscopy and magnetic measurements were employed to characterize the complexes. The results confirmed the formation of the ligand and the complex. The interaction of the complex with calf thymus DNA (CT-DNA) has been carried out using UV-visible titration, fluorescence spectroscopy, cyclic voltammetry and viscosity measurements. The intrinsic binding constant (Kb) and Stern-Volmer constant (Ksv) of the complexes have been calculated. The cleavage activity of the ligand and the complexes with pBR322 DNA was further confirmed by gel electrophoretic technique. The pharmacological activity of the ligand and the complexes was investigated by antioxidant, antimicrobial and cytotoxic activity, and they show promising pharmacological effect. The results of the molecular docking studies of the ligand and the complexes reinforce all the above facts.
TL;DR: In this article, Ni-doped TiO2 nanorods were fabricated on indium tin oxide (ITO) coated glass substrate by a novel spray pyrolysis deposition route.
Abstract: In the present work, Ni-doped TiO2 nanorods were fabricated on indium tin oxide (ITO) coated glass substrate by a novel spray pyrolysis deposition route. The influence of pyrolytic temperature on the degree of crystallinity of the Ni:TiO2 films was clearly reflected in the X-ray diffractograms. The promoting effect of ITO seed layer on Ni:TiO2 film was reflected in the film prepared at 300 °C which show predominantly a (101) orientation corresponding to the c-axis of pure tetragonal anatase TiO2. The evaluated optical band gap (Eg) of the films prepared at different temperature was in the range of 3.3–3.62 eV. The high Eg values confirmed the existence of TiO2–Ni catalyst influence interaction. The morphology of the film optimized at 300 °C was almost rod shaped with large roughness favorable for sensing. The hydrogen sensing properties of the Ni:TiO2 nanorod sensor was investigated. The Ni doped TiO2 films exhibited a different p-type response to H2. It was found that the sensor based on Ni:TiO2 nanorod structure optimized at 300 °C exhibited good performance even at room temperature.
TL;DR: In this article, a simple soft chemical route was used to synthesize ZnO:Zr nanopowders with different levels of Mn doping, ranging from 0, 1.5 and 9 at.
Abstract: Zr and Zr + Mn doped ZnO nanopowders were synthesized using a simple soft chemical route keeping the Zr concentration in the precursor solution constant (3 at.%) and varying the Mn concentration (0, 1.5 and 9 at.%). From the X-ray diffraction studies, the crystallite size of ZnO:Zr nanopowder is found as 57 nm. The crystallite size decreases with the increase in the Mn doping level and attains a minimum of 23 nm
at the maximum doping level examined in the present work (9 at.%). The Zr doped ZnO nanopowders found to have ferromagnetic property. The saturation magnetization increases with the increase in the Mn doping level and attains a maximum value at 7 at.% of Mn doping. The material shows superparamagnetic behavior at the doping level of 9 at.%. The antibacterial efficiency is found to be maximum at 9 at.% of Mn doping and at this doping level the grain size is minimum (20 nm) as evidenced from the SEM and TEM results.