We report a simple one-pot microwave assisted "green synthesis" of Graphene Quantum Dots (GQDs) using grape seed extract as a green therapeutic carbon source. These GQDs readily self-assemble, ...hereafter referred to as "self-assembled" GQDs (sGQDs) in the aqueous medium. The sGQDs enter via caveolae and clathrin-mediated endocytosis and target themselves into cell nucleus within 6-8 h without additional assistance of external capping/targeting agent. The tendency to self-localize themselves into cell nucleus also remains consistent in different cell lines such as L929, HT-1080, MIA PaCa-2, HeLa, and MG-63 cells, thereby serving as a nucleus labelling agent. Furthermore, the sGQDs are highly biocompatible and act as an enhancer in cell proliferation in mouse fibroblasts as confirmed by in vitro wound scratch assay and cell cycle analysis. Also, photoluminescence property of sGQDs (lifetime circa (ca.) 10 ns) was used for optical pH sensing application. The sGQDs show linear, cyclic and reversible trend in its fluorescence intensity between pH 3 and pH 10 (response time: ~1 min, sensitivity -49.96 ± 3.5 mV/pH) thereby serving as a good pH sensing agent. A simple, cost-effective, scalable and green synthetic approach based sGQDs can be used to develop selective organelle labelling, nucleus targeting in theranostics, and optical sensing probes.
► Non-thermal plasma degradation and mineralization of methylene blue in water. ► Confirmation of mineralization by TOC and infrared gas analyzers. ► Improved performance with the addition of Fe+2 ...via Fenton type reaction. ► High energy efficiency for the dye removal (67g/kWh). ► Confirmation of first order kinetics for the dye removal.
Advanced oxidation process based on dielectric barrier discharge at the gas water interface was used for the oxidative decomposition of dye contaminated wastewater. The advantage of plasma treatment over conventional physical methods of pollutants removal is the mineralization of pollutant, whereas in physical methods, pollutants may be transferred from one form to another. The effect of various parameters like applied voltage, gas flow rate, concentrations of dye, addition of Na2SO4 and Fe2+, formation of H2O2 and change in pH were investigated for methylene blue degradation. The high degradation yield up to 67g/kWh was achieved during the present study. Hydrogen peroxide, a powerful oxidant formed during the reaction was confirmed and addition of Fe+2 improved the performance, possibly due to Fenton type reactions. It has been observed that dye degradation followed first order kinetics.
We report a simple one-pot microwave-assisted green-synthesis route for the fabrication of bright red-luminescent graphene quantum dots (GQDs) using ethanolic extracts of Mangifera indica (mango) ...leaves, hence addressing them as mGQDs. The mGQDs were quantum-sized ranging from 2 to 8 nm and exhibited excitation-independent fluorescence emission in the near-infrared (NIR) region between 650 and 750 nm. The mGQDs showed defects in their structure and were highly crystalline in nature as confirmed by Raman spectroscopy and powdered X-ray diffraction analysis, respectively. These mGQDs showed 100% cellular uptake and excellent biocompatibility on L929 cells even at high concentration (0.1 mg/mL) 24 h post-treatment. Cell cycle analysis showed increased proliferation in L929 cells upon mGQDs treatment. Furthermore, the mGQDs were demonstrated as NIR-responsive fluorescent bioimaging probes, self-localizing themselves selectively in the cell cytoplasm. Also, the temperature-dependent fluorescence intensity of these GQDs proved them as a very competent temperature sensing probe (at 10–80 °C). The temperature sensing stability analysis showed that the temperature signal remains stable even after multiple cycles of temperature switching between 30–80 °C. Furthermore, we analyzed intracellular temperature (25–45 °C) of live L929 cells based on the fluorescence intensity of the mGQDs. It was observed that with an increasing temperature there was a decrease in the fluorescence intensity of the mGQDs making it a suitable probe for temperature sensing. In sum, a biocompatible, scalable, photostable, green synthesis based mGQDs were prepared for NIR imaging and nanothermometry applications which can play a pivotal role in biomedical nanotechnology.
The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General ...Circulation Model (GCM) of future data on daily maximum (T.max), minimum (T.min) air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1). This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF) -2020, Distant future (DF)-2050 and Very Distant future (VDF)-2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1-2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18-22% over baseline. Analysis of variance (ANOVA) was used to partition the variation in the predicted number of generations and generation time of S. litura on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%), model (1.74%) and scenario (0.74%). The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of S. litura may increase due to projected increase in temperatures in future climate change periods.
Trivalent rare earth ions show interesting optical properties and such properties have high technological applications of rare earth doped materials such as energy saving lighting devices, optical ...displays, optical fibers, amplifiers and lasers. Among these materials rare earth ions doped glasses are of great important to optoelectronics and are widely used in fiber amplifiers and solid state high power lasers for telecommunications and light emitting diodes. Near-infrared luminescence for high power lasers is a current requirement in modern fiber optic telecommunication network and emphasis has to put in recent advances of NIR emitting materials for amplifiers, fiber lasers and waveguides. We make an effort to satisfy the above needs by preparing the LCZSFB glasses doped with Sm3+, Dy3+, Eu3+, Tb3+ and Nd3+ rare earth ions. In this review, optical properties of LCZSFB glasses doped with Sm3+, Dy3+, Eu3+, Tb3+ and Nd3+ rare earth ions and the current status of their applications is given.
To sustain the complexity of growing demand, the conventional grid (CG) is incorporated with communication technology like advanced metering with sensors, demand response (DR), energy storage systems ...(ESS), and inclusion of electric vehicles (EV). In order to maintain local area energy balance and reliability, microgrids (MG) are proposed. Microgrids are low or medium voltage distribution systems with a resilient operation, that control the exchange of power between the main grid, locally distributed generators (DGs), and consumers using intelligent energy management techniques. This paper gives a brief introduction to microgrids, their operations, and further, a review of different energy management approaches. In a microgrid control strategy, an energy management system (EMS) is the key component to maintain the balance between energy resources (CG, DG, ESS, and EVs) and loads available while contributing the profit to utility. This article classifies the methodologies used for EMS based on the structure, control, and technique used. The untapped areas which have scope for investigation are also mentioned.
Series of 4H-chromen-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 7a–7zb, 8a–8d and 9a–9d were synthesized and screened for their in vitro anti-mycobacterial activity against Mycobacterium ...tuberculosis H₃₇Rv (MTB) and cytotoxicity against three human cancer cell lines including A549, SK-N-SH and HeLa. The results indicate that six compounds are more potent and 7za is most effective anti-mycobacterial derivative compared to the standard drugs Ethambutol and Ciprofloxacin. However, 12 compounds exhibited cytotoxicity against human neuroblastoma cell line; amongst them the compound 7v is most effective compared to the standard drug Doxorubicin. This is the first report assigning in vitro anti-mycobacterial, anticancer and structure–activity relationship for this new class of 4H-chromen-1,2,3,4-tetrahydropyrimidine-5-carboxylates.
Imaging-based methods of food portion size estimation (FPSE) promise higher accuracies compared to traditional methods. Many FPSE methods require dimensional cues (fiducial markers, ...finger-references, object-references) in the scene of interest and/or manual human input (wireframes, virtual models). This paper proposes a novel passive, standalone, multispectral, motion-activated, structured light-supplemented, stereo camera for food intake monitoring (FOODCAM) and an associated methodology for FPSE that does not need a dimensional reference given a fixed setup. The proposed device integrated a switchable band (visible/infrared) stereo camera with a structured light emitter. The volume estimation methodology focused on the 3-D reconstruction of food items based on the stereo image pairs captured by the device. The FOODCAM device and the methodology were validated using five food models with complex shapes (banana, brownie, chickpeas, French fries, and popcorn). Results showed that the FOODCAM was able to estimate food portion sizes with an average accuracy of 94.4%, which suggests that the FOODCAM can potentially be used as an instrument in diet and eating behavior studies.
•Mixed convective heat transfer for magnetohydrodynamic flow past a sphere.•Relationship is established between drag coefficient and interaction parameter.•Three different regimes are identified ...based on variation of Nusselt number.•Heat transfer varies strongly with Re, interaction parameter and Richardson number.•Correlations are developed for drag coefficient and average Nusselt number.
Numerical computations are performed to examine the flow and heat transfer characteristics for mixed convective flow past a sphere in an assisting flow arrangement with an aligned magnetic field. The flow is considered as laminar, steady and incompressible and the working fluids as Newtonian. A spherical geometry higher order compact scheme (SGHOCS) is employed to solve the set of non-linear governing transport equations. The results are enumerated in terms of streamlines, isotherms, drag coefficient together with local and average Nusselt number on the surface of the sphere by varying the following parameters: Reynolds number 1 ≤ Re ≤ 200; Prandtl number 0.72 and 7; Richardson number 0 ≤ Ri ≤ 1.5; interaction magnetic parameter 0 ≤ N ≤ 10. For lower values of Ri, although the flow separation phenomena in the downstream region suppresses for weaker strength of the magnetic field (N ≤ 0.5), it again increases on further increase in N. For higher values of Ri, with an increase of N, the flow separation phenomena completely suppresses. The drag coefficient (CD) increases with N for any values of Re, Ri and Pr and for N ≥ 1, CD=KN+B where K and B are constants that depends on Ri and Pr and K = 0.32 for Ri = 0 which is consistent with the results in the literature. On the basis of variation of Nu on the sphere surface, three different regions are identified and moreover a strong interplay between N and Ri in dictating the characteristic of heat transfer is found for all values of Re. In the mixed convection domain the average Nusselt number (Nu¯) first decreases with N and then tends to a constant value for higher values of Reynolds number, in contrast with the forced convection case, when Nu¯ decreases with N and then tends to increase almost linearly with N. Based on the numerical results for the considered range of parameters, correlations are developed for CD and Nu¯, which are relatively in good agreement with reported results in the literature for special cases of both forced and mixed convective flows past a sphere in the absence of a magnetic field.
Niobium containing tellurium calcium zinc borate (TCZNB) glasses doped with different concentrations of Dy3+ ions were prepared by the melt quenching method and their optical properties have been ...studied. The Judd–Ofelt (J–O) intensity parameters Ωt (t=2, 4 and 6) were calculated using the least square fit method. Based on the magnitude of Ω2 parameter the hypersensitivity of 6H15/2→6F11/2 has also been discussed. From the evaluated J–O intensity parameters as well as from the emission and lifetime measurements, radiative transition properties such as radiative transition probability rates and branching ratios were calculated for 4F9/2 excited level. It is found that for Dy3+ ion, the transition 4F9/2→6H13/2 shows highest emission cross-section at 1.0mol% TCZNB glass matrix. From the visible luminescence spectra, yellow to blue (Y/B) intensity ratios and chromaticity color coordinates were also estimated. The TCZNB glasses exhibit good luminescence properties and are suitable for generation of white light.
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