54 research outputs found

    Spectroscopic, thermal, second order and third order NLO studies of N, N’ -dimethyl urea crystal

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    Nonlinear optical (NLO) crystals are classified into organic, inorganic and semi organic crystals and these crystals are used in the fields of optical communication, optical computing, frequency doubling, optical data processing and opto electronics. In this work an organic NLO crystal namely DMU crystal was prepared. Slow evaporation technique was adopted to grow the single crystals of DMU after the growth period of 35 days. The harvested crystals have been subjected to various characterization techniques like XRD, FTIR, FT-Raman, TG/DTA, SHG, EDAX, impedance, optical and Z-scan studies. From the studies, is observed that DMU crystal has orthorhombic structure and it has the melting point at 105 oC and has the decomposition point at 275 oC. The relative SHG efficiency of DMU crystal was found to be more than one and third order NLO parameters were evaluated. The optical band gap of DMU crystal was found to be 5.008 eV.The results from various studies were analyzed.

    Application of Genetic Algorithm Technique for Machining Parameters Optimization in Drilling of Stainless Steel

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    Abstract This work is aimed at developing relations between the pertinent variables that affect drilling process of stainless steel using artificial neural network. The experiments were conducted on vertical CNC machining centre. The parameters used were spindle speed and feed rate. The effect of machining parameters on entry burr height, exit burr height and surface roughness was experimentally evaluated for different spindle speeds and feed rates. A model was established between the drilling parameters and experimentally obtained data using ANN. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the burr height and surface roughness in drilling of stainless steel. Genetic algorithm (GA) technique was used in this work to identify the optimized drilling parameters. Confirmation test was conducted with the optimized parameters and it was found that confirmation test results were similar to that of GA-predicted output values

    Adaptive display power management for mobile games

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    Ministry of Education, Singapore under its Academic Research Funding Tier

    A window into fungal endophytism in Salicornia europaea: deciphering fungal characteristics as plant growth promoting agents

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    Aim Plant-endophytic associations exist only when equilibrium is maintained between both partners. This study analyses the properties of endophytic fungi inhabiting a halophyte growing in high soil salinity and tests whether these fungi are beneficial or detrimental when non-host plants are inoculated. Method Fungi were isolated from Salicornia europaea collected from two sites differing in salinization history (anthropogenic and naturally saline) and analyzed for plant growth promoting abilities and non-host plant interactions. Results Most isolated fungi belonged to Ascomycota (96%) including dematiaceous fungi and commonly known plant pathogens and saprobes. The strains were metabolically active for siderophores, polyamines and indole-3-acetic acid (mainly Aureobasidium sp.) with very low activity for phosphatases. Many showed proteolytic, lipolytic, chitinolytic, cellulolytic and amylolytic activities but low pectolytic activity. Different activities between similar fungal species found in both sites were particularly seen for Epiccocum sp., Arthrinium sp. and Trichoderma sp. Inoculating the non-host Lolium perenne with selected fungi increased plant growth, mainly in the symbiont (Epichloë)-free variety. Arthrinium gamsii CR1-9 and Stereum gausapatum ISK3-11 were most effective for plant growth promotion. Conclusions This research suggests that host lifestyle and soil characteristics have a strong effect on endophytic fungi, and environmental stress could disturb the plant-fungi relations. In favourable conditions, these fungi may be effective in facilitating crop production in non-cultivable saline lands

    Microwave Irradiation Effect on Structural, Optical, and Thermal Properties of Cadmium Oxide Nanostructure

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    Cadmium oxide nanostructures were prepared by microwave assisted wet chemical technique at different time intervals. Results on structural, optical, and thermal properties of the CdO nanostructures as a function of the microwave irradiation were reported. The X-ray diffraction data indicates that the sample showed perfection in the microstructural improvement as a function of microwave irradiation. Surface morphological changes with different time of microwave irradiation were recorded by transmission electron microscope and the particle size were found in the ranges from 5 to 30 nm. Chemical composition and thermal stability of the samples were analyzed by energy dispersive X-ray spectrum and thermogravimetric analysis, respectively. The band gaps were shifted towards the blue region due to the Moss-Burstein effect and it exhibited direct band transitions, which corresponds to optical band gaps of 3.92-4.20 eV and contrast behavior of optical properties of CdO nanostructure in UV and IR regions were registered. Room temperature photoluminescence spectra revealed that the intensity of luminescent emission tends to decrease with the increase in exposure of microwave irradiation

    <i>In vivo </i> evaluation of anti-MRSA compound from <i>Streptomyces collinus </i> ICN1 in zebrafish embryos

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    1155-1161Streptomyces collinus ICN1, an endosymbiotic actinomycete, isolated from the marine sponge Echinodictyum gorgonoides collected from Kanyakumari coast was studied for its antagonistic activity against the clinical pathogen Methicillin-resistant Staphylococcus aureus (MRSA). 16S rRNA gene sequencing confirmed the strain was related to Streptomyces collinus and spore morphology showed smooth surface in scanning electron microscopy. Media optimization for anti MRSA compound production was carried out in solid state fermentation using defined parameters, followed by extraction in methanol. Antagonistic anti-MRSA compound showed 0.91 Rf value in the Thin layer chromatography analysis and 1.53 min retention time in the high performance liquid chromatography analysis at the wavelength of 236 nm. Antagonistic activity of purified compound was studied against MRSA in both in vitro antibacterial assays and in vivo biocompatibility studies in zebrafish embryos. Minimum inhibitory concentration of the compound was found to be 2 µg/ ml by in vitro broth micro dilution method and 4X MIC dose of the compound effective enough to inhibit the pathogenicity of MRSA in in vivo zebrafish infection assay and for the survival of embryos

    The Unprecedented Role of 3D Printing Technology in Fighting the COVID-19 Pandemic: A Comprehensive Review

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    The coronavirus disease 2019 (COVID-19) rapidly spread to over 180 countries and abruptly disrupted production rates and supply chains worldwide. Since then, 3D printing, also recognized as additive manufacturing (AM) and known to be a novel technique that uses layer-by-layer deposition of material to produce intricate 3D geometry, has been engaged in reducing the distress caused by the outbreak. During the early stages of this pandemic, shortages of personal protective equipment (PPE), including facemasks, shields, respirators, and other medical gear, were significantly answered by remotely 3D printing them. Amidst the growing testing requirements, 3D printing emerged as a potential and fast solution as a manufacturing process to meet production needs due to its flexibility, reliability, and rapid response capabilities. In the recent past, some other medical applications that have gained prominence in the scientific community include 3D-printed ventilator splitters, device components, and patient-specific products. Regarding non-medical applications, researchers have successfully developed contact-free devices to address the sanitary crisis in public places. This work aims to systematically review the applications of 3D printing or AM techniques that have been involved in producing various critical products essential to limit this deadly pandemic&rsquo;s progression
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