Showing papers by "Annamalai University published in 2015"
TL;DR: The current study has clearly demonstrated that the particle size variations and surface area to volume ratios of ZnO NPs are responsible for significant higher antibacterial activities.
414 citations
TL;DR: In this article, the synthesis of zinc oxide nanoparticles (ZnO NPs) using leaf aqueous extract of Azadirachta indica (L.) and its antimicrobial activities was described.
394 citations
TL;DR: Biosurfactants produced by microorganisms have potential applications in pharmaceutical/medicine, food, cosmetic, pesticide, oil, and biodegradation industries and are found to have a wide range of applications in environmental protection.
Abstract: Biosurfactants are surface-active biomolecules produced by microbes (bacteria, fungi, and yeast) and have several advantages over the chemical surfactants, such as lower toxicity, higher biodegradability, better environmental compatibility, higher foaming, high selectivity, and specific activity under extreme conditions such as temperature, pH, and salinity. Almost all the surfactants now available in the market are chemically synthesized. Recently, attention toward the biosurfactants was doubled, which is mainly due to their wide range of functional properties and the diverse synthetic capabilities of the microbes. Microbial biosurfactants are found to have a wide range of applications in environmental protection, which include enhancing oil recovery, controlling oil spills, biodegradation, and detoxification of oil-contaminated industrial effluents and soils. Biosurfactants produced by microorganisms have potential applications in pharmaceutical/medicine, food, cosmetic, pesticide, oil, and biodegradati...
270 citations
TL;DR: In this paper, a seaweed extract was used for the synthesis of AgNO3 at room temperature, which showed the best antibacterial activity against human pathogens such as Staphylococcus aureus and Proteus mirabilis.
Abstract: We present the synthesis and antibacterial activity of silver nanoparticles using Caulerpa racemosa ,a marine algae. Fresh C. racemosa was collected from the Gulf of Mannar, Southeast coast of India. The seaweed extract was used for the synthesis of AgNO3 at room temperature. UV-visible spectrometry study revealed sur- face plasmon resonance at 413 nm. The characterization of silver nanoparticle was carried out using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscope (TEM). FT-IR measurements revealed the possible functional groups responsible for reduction and stabilization of the nanopar- ticles. X-ray diffraction analysis showed that the particles were crystalline in nature with face-centered cubic geom- etry.TEM micrograph has shown the formation of silver nanoparticles with the size in the range of 5-25 nm. The synthesized AgNPs have shown the best antibacterial activity against human pathogens such as Staphylococcus aureus and Proteus mirabilis. The above eco-friendly synthesis procedure of AgNPs could be easily scaled up in future for the industrial and therapeutic needs.
264 citations
TL;DR: Results of vibrating sample magnetometer (VSM) indicated that the prepared Fe3O4 nanoparticles exhibit superparamagnetic behavior and high saturation magnetization at room temperature.
201 citations
TL;DR: It was investigated that the synthesized AgNPs showed inhibition and had significant antibacterial against both gram-positive and gram-negative bacterial strains and AFM has proved to be very helpful in the determination and verification of various morphological features and parameters.
177 citations
TL;DR: In this paper, the authors used 2-propanol and 2-tetra iso propoxide (2-Propanol) as starting materials and the obtained products were calcined at 500 and 800°C to get anatase and rutile phases, respectively.
Abstract: TiO2 nanoparticles doped with different concentrations of cobalt (4, 8, 12 and 16 %) were synthesized by sol–gel method at room temperature with appropriate reactants. In general, TiO2 can exist in anatase, rutile, and brookite phases. In this present study, we used titanium tetra iso propoxide and 2-propanol as a common starting materials and the obtained products were calcined at 500 °C and 800 °C to get anatase and rutile phases, respectively. The crystalline sizes of the doped and undoped TiO2 nanoparticles were observed with X-ray diffraction (XRD) analysis. The functional groups of the samples were identified by Fourier transform infrared spectroscopy (FTIR). From UV–VIS diffuse reflectance spectra (DRS), the band gap energy and excitation wavelength of doped and undoped TiO2 nanoparticles were identified. The defect oriented emissions were seen from photoluminescence (PL) study. The spherical uniform size distribution of particles and elements present in the samples was determined using two different techniques viz., scanning electron microscopy (SEM) with energy-dispersive spectrometer (EDX) and transmission electron microscope (TEM) with selected area electron diffraction (SAED) pattern. The second harmonic generation (SHG) efficiency was also found and the obtained result was compared with potassium di hydrogen phosphate (KDP).
169 citations
TL;DR: The results of antimicrobial activities revealed that maximum zones of inhibition was observed Gram (+ve) positive bacteria and followed by the Gram (-ve) negative bacteria and fungal at concentration of 200μg/mL of ZnO NPs.
168 citations
TL;DR: In this article, a comparative evaluation of mechanical properties and microstructural features of shielded metal arc, gas metal arc and friction stir welded (FSW) naval grade HSLA steel joints was carried out.
158 citations
TL;DR: In this article, an attempt has been made to join the heat treatable and non-heat treatable (AA 5086) aluminium alloys by friction stir welding (FSW) process using three different tool pin profiles.
156 citations
TL;DR: The present investigation confirmed the estimated band gap 3.51eV and the PL intensity at 402nm in visible region are dependent upon the geometrical shape and size of the ZnO NPs.
University of Hyderabad1, Indian Institute of Technology Kharagpur2, International Centre for Integrated Mountain Development3, Indian Institute of Remote Sensing4, Remote Sensing Center5, TERI University6, Banaras Hindu University7, University of Twente8, International Water Management Institute9, Centre for Development of Advanced Computing10, International Center for Agricultural Research in the Dry Areas11, Wildlife Institute of India12, Annamalai University13, Berhampur University14, United Nations University15, Indian Institutes of Information Technology16, University of Agricultural Sciences, Dharwad17, World Agroforestry Centre18, University of Kashmir19, National Botanical Research Institute20, Assam University21, Kerala Forest Research Institute22, North Orissa University23, Botanical Survey of India24, University of Calcutta25, Lincoln University (Pennsylvania)26, Pondicherry University27, Mohanlal Sukhadia University28, University of Jammu29, Council of Scientific and Industrial Research30
TL;DR: This vegetation type map is the most comprehensive one developed for India so far and was prepared using 23.5 m seasonal satellite remote sensing data, field samples and information relating to the biogeography, climate and soil.
TL;DR: In this article, a simple combination reaction between zinc nitrate and leaf extract of Anisochilus carnosus was described to prepare ZnO nanoparticles, which were subjected to structural, optical, and morphological analyses.
TL;DR: The wastewater generated during wet-blue tanning process can support dense population of Scenedesmus sp.
Abstract: A number of microalgae species are efficient in removing toxicants from wastewater. Many of these potential species are a promising, eco-friendly, and sustainable option for tertiary wastewater tre...
TL;DR: In this paper, a bat-inspired algorithm based dual mode PI controller is applied to the multi-area interconnected thermal power system in order to tune the parameter PI controllers, which provides better transient as well as steady state of response.
TL;DR: In this article, a single cylinder, common rail direct injection (CRDI) system assisted diesel engine using diesel with 25 percentage of zizipus jujube methyl ester blended fuel (ZJME25) was evaluated.
Abstract: Experiments were conducted to determine engine performance, exhaust emissions and combustion characteristics of a single cylinder, common rail direct injection (CRDI) system assisted diesel engine using diesel with 25 percentage of zizipus jujube methyl ester blended fuel (ZJME25). Along with this ZJME25 aluminium oxide nanoparticles were added as additive in mass fractions of 25 ppm (AONP 25) and 50 ppm (AONP 50) with the help of a mechanical Homogenizer and an ultrasonicator. It was observed that aluminium oxide nanoparticles blended fuel exhibits a significant reduction in specific fuel consumption and exhaust emissions at all operating loads. At the full load, the magnitude of HC and smoke emission for the ZJME25 before the addition of aluminium oxide nanoparticles was 13.459 g/kW h and 79 HSU, whereas it was 8.599 g/kW h and 49 HSU for the AONP 50 blended ZJME25 fuel respectively. The results also showed a considerable enhancement in brake thermal efficiency and heat release rate due to the influence of aluminium oxide nanoparticles addition in biodiesel–diesel blend.
TL;DR: In this paper, the zinc oxide nanoparticles (ZnO NPs) were synthesized from the leaf extract of Vitex trifolia L. The major chemical components identified were Vitrifolin A (22.11%), 20-hydroxyecdysone (13.78%), 5-Thio d -glucose (10.32%), and 1,1-Bicyclopropyl-2-octanoic acid,2′-hexyl; methyl ester (8.33%).
TL;DR: In this article, the optimal placement and sizing of DG units play a major role in reducing system losses and in improving voltage profile and voltage stability, and the proposed algorithm is validated by testing it on a 38-node and 69-node radial distribution system.
TL;DR: The AgNPs thus obtained showed highly potent antibacterial activity toward Gram-positive (Staphyloccocus aureus and Bacillus subtilis) and Gram-negative (Salmonella typhi and Escherichia coli) microorganisms.
TL;DR: Acid and Pepsin soluble collagens isolated from the outer skin of squid skin could serve as an alternative source of collagen for further application in food, nutraceutical and pharmaceutical industries.
TL;DR: In this article, the effect of pH on nanoparticle synthesis was determined by adjusting the various pH of the reaction mixtures, and the crystalline nature of nanoparticles was confirmed from the XRD pattern and the grain size was found to be around 34nm.
Abstract: Biosynthesis of metallic silver nanoparticles has now become an alternative to physical and chemical approaches. In the present study, silver nanoparticles (AgNPs) were synthesized from Cavendish banana peel extract (CBPE) and characterized by UV–visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Atomic force microscopy (AFM), Field emission scanning electronic microscope (FESEM), Dynamic light scattering (DLS) and zeta potential (ZP). The AgNPs formation was confirmed by UV–visible spectroscopy through color conversion due to surface plasma resonance band at 430 nm. The effect of pH on nanoparticle synthesis was determined by adjusting the various pH of the reaction mixtures. The crystalline nature of nanoparticles was confirmed from the XRD pattern, and the grain size was found to be around 34 nm. To identify the compounds responsible for the bioreduction of Ag+ ion and the stabilization of AgNPs produced, the functional group present in Cavendish banana peel extract was investigated using FTIR. AFM has proved to be very helpful in determining morphological features and the diameter of AgNPs in the range of 23–30 nm was confirmed by FESEM. DLS studies revealed that the average size of AgNPs was found to be around 297 nm. Zeta potential value for AgNPs obtained was −11 mV indicating the moderate stability of synthesized nanoparticles. The antibacterial activity of the nanoparticles was studied against Gram-positive and Gram-negative bacteria. Biosynthesized AgNPs showed a strong DPPH radical and ABTS scavengers compared to the aqueous peel extract of Cavendish banana.
TL;DR: The synthesized silver nanoparticles synthesized by using the leaf extract of Croton sparsiflorus morong Ag NPs were characterized by using UV-Visible absorption spectroscopy, X-ray diffraction, Field Emission Scanning Electron Microscopy and Fourier Infrared Spectroscopy for the significant antimicrobial activities.
TL;DR: The effects of hesperidin in iron induced hepatic and renal function and its reduced lipid profile were evaluated to rescue the liver and kidney tissues from pathology.
Abstract: The present study was to evaluate the protective role of hesperidin (HDN) against iron-induced hepatic and renal toxicity in rats. Administration of iron (30 mg/kg body weight) intraperitoneally for 10 days, the levels of serum hepatic markers, renal functional markers, lipid profile, lipid peroxidation markers and iron concentration in blood were significantly (p < 0.05) increased. The toxic effect of iron was also indicated by significant (p < 0.05) decrease in the levels of plasma, liver and kidney of enzymatic and non-enzymatic antioxidants. Administration of hesperidin at different doses (20, 40 and 80 mg/kg body weight) significantly (p < 0.05) reversed the levels of serum hepatic markers, renal functional markers, lipid profile, lipid peroxidation markers, restored the levels of hepatic, renal enzymatic antioxidants and non-enzymatic antioxidants with decrease in iron concentration in blood. Hesperidin at a dose of 80 mg/kg body weight exhibits significant protection on hepatic and renal when compared with other two doses (20 and 40 mg/kg body weight). All these changes were corroborating by histological observations of liver and kidney. This study demonstrated the protective role of hesperidin in reducing toxic effects of iron in experimental rats.
TL;DR: The diverse biological activities of Fucoidan include anticancer, anti inflammatory and antimicrobial but the α-d-glucosidase inhibitory activity of native fucoidan from S. wightii for type 2 diabetes therapy is first of its kind.
TL;DR: In this paper, an approach to better estimate the groundwater recharge potential zones using geographical information system (GIS), influence factor and RS techniques has been applied in Ottapidaram taluk in Tuticorin district, where various thematic layers such as: lithology, slope, land use, lineament, drainage, soil, and rainfall were transformed into raster data using the feature to raster converter tool in ArcGIS 9.3 software.
Abstract: This study is an approach to better estimate the groundwater recharge potential zones using geographical information system (GIS), influence factor and RS techniques. This concept has been applied in Ottapidaram taluk in Tuticorin district to determine the overall groundwater recharge potentiality. Survey of India toposheets and Indian Remote Sensing-1C satellite imageries are used to prepare various thematic layers such as: lithology, slope, land use, lineament, drainage, soil, and rainfall. These layers were then transformed into raster data using the feature to raster converter tool in ArcGIS 9.3 software. Subjective weights are assigned to the respective thematic layers and overlaid in GIS platform for the identification of potential groundwater zones within the study area. These potential zones were categorized as ‘high’, ‘moderate’, and ‘low’ zones with respect to the assigned weightage of different thematic layers. The results reveal that the areas of good groundwater potential are estimated to cover 260.25 km2 (35 % of the study area), moderate potential 297.43 km2 (40 %), and low potential 185 km2 (25 %). Moreover, only 34 % of the total average annual precipitated water (680 mm) percolates into subsurface and ultimately contributes to recharge the groundwater. These results suggest that the high potential zones will have a key role in future expansion of drinking water and irrigation development in the study area.
TL;DR: From this analysis, it is confirmed that the contents of clay and organic matter play an important role to raise the level of heavy metal contents as well as PLI and PER (level of toxicity).
TL;DR: It is concluded that hesperidin can reverse memory loss caused by aluminum intoxication through attenuating AChE activity and amyloidogenic pathway.
Abstract: The present study was aimed to evaluate the protective effect of hesperidin (Hes) on aluminium chloride (AlCl3) induced neurobehavioral and pathological changes in Alzheimeric rats. Intraperitonial injection of AlCl3 (100 mg/kg body weight) for 60 days significantly elevated the levels of aluminium (Al), activity of acetylcholinesterase (AChE) and protein expressions of amyloid precursor protein (APP), β amyloid (Aβ1–42), β and γ secretases as compared to control group in hippocampus and cortex of rat brain. Hes administration orally along with AlCl3 injection for 60 days, significantly revert the Al concentration, AChE activity and Aβ synthesis-related molecules in the studied brain regions. Our results showed that aluminum exposure was significantly reduced the spontaneous locomotor and exploratory activities in open field test and enhanced the learning and memory impairments in morris water maze test. The behavioral impairments caused by aluminum were significantly attenuated by Hes. The histopathological studies in the hippocampus and cortex of rat brain also supported that Hes (100 mg/kg) markedly reduced the toxicity of AlCl3 and preserved the normal histoarchitecture pattern of the hippocampus and cortex. From these results, it is concluded that hesperidin can reverse memory loss caused by aluminum intoxication through attenuating AChE activity and amyloidogenic pathway.
TL;DR: Treatment with lycopene reverses neurochemical deficts, oxidative stress, apoptosis and physiological abnormalities in PD mice and offer promise strategy in the treatment of this neurodegenerative disease.
TL;DR: It is concluded that thymol may exhibit promising anti-diabetic activity and protects C57BL/6J mice against HFD due to its anti- hyperglycaemic and anti-hyperlipidemic activity.
TL;DR: This is the first report on mosquito larvicidal activity of plant-synthesized nanoparticles and the use of G. asiatica to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach and the AgNps formed can be potential mosquito larVicidal agents.
Abstract: Mosquitoes are blood-feeding insects and serve as the most important vectors for spreading human diseases such as malaria, yellow fever, dengue fever, and filariasis The continued use of synthetic insecticides has resulted in resistance in mosquitoes Synthetic insecticides are toxic and affect the environment by contaminating soil, water, and air, and then natural products may be an alternative to synthetic insecticides because they are effective, biodegradable, eco-friendly, and safe to environment Botanical origin may serve as suitable alternative biocontrol techniques in the future The present study was carried out to establish the larvicidal potential of leaf extracts of Gmelina asiatica and synthesized silver nanoparticles using aqueous leaf extract against late third instar larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus Larvae were exposed to varying concentrations of plant extracts and synthesized AgNPs for 24 h The results were recorded from UV–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy analysis support the biosynthesis and characterization of AgNPs The maximum efficacy was observed in synthesized AgNPs against the larvae of An stephensi (lethal dose (LC50) = 2244 μg/mL; LC90 4065 μg/mL), Ae aegypti (LC50 = 2577 μg/mL; LC90 4598 μg/mL), and C quinquefasciatus (LC50 = 2783 μg/mL; LC90 4892 μg/mL), respectively No mortality was observed in the control This is the first report on mosquito larvicidal activity of plant-synthesized nanoparticles Thus, the use of G asiatica to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach and the AgNps formed can be potential mosquito larvicidal agents