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•Nutrients and salinity influence the carotenoid composition in microalgae.•Maximum carotenoid content in Synechocystis sp. CCNM 2501 is 7.99mgg−1 DW.•>4 folds higher echinenone in ...Zarrouk’s media as compared to BG11 and Chu’s 10.•>3 folds higher β-carotene in 1M salinity compared with non saline medium.
Nutrients are the deciding factors in the biological production of bioactive compounds. Various growth media like BG11, Zarrouk’s and Chu’s 10 were studied for carotenoid production in Synechocystis sp. CCNM 2501. Maximum carotenoid content (dry weight basis) was found in Zarrouk’s medium (ZM, 7.99mgg−1) followed by BG11 (5.13mgg−1). Echinenone content was 4 times higher in ZM (3.81mgg−1) as compared to BG11 (0.95mgg−1) and Chu’s 10 (0.77mgg−1). Being an economical medium, BG11 was selected for carotenoid production. Further, increase in salinity from 0 to 0.2M in BG11 medium increases total carotenoid content from 5.82 to 7.05mgg−1 and later it declines to 6.23mgg−1 (1M). 3 times more β-carotene is produced at 1M salinity as compared to control BG11. The variation in carotenoid composition with change in nutrients/salinity can be a good strategy to enhance certain targeted carotenoids.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Highly specific graphene-DNA interactions have been at the forefront of graphene-based sensor design for various analytes, including DNA itself. However, in addition to its detection, DNA also needs ...to be characterized according to its size and concentration in a sample, which is an additional analytical step. Designing a highly sensitive and selective DNA sensing and characterization platform is, thus, of great interest. The present study demonstrates that a bio-derived, naturally fluorescent protein C-phycoerythrin (CPE) – graphene oxide (GO) bio-composite can be used to detect dsDNA in nanomolar quantities efficiently via fluorescent “turn off/on” mechanism. Interaction with GO temporarily quenches CPE fluorescence in a dose-dependent manner. Analytical characterization indicates an indirect charge transfer with a corresponding loss of crystalline GO structure. The fluorescence is regained with the addition of DNA, while other biomolecules do not pose any hinderance in the detection process. The extent of regain is DNA length dependent, and the corresponding calibration curve successfully quantifies the size of an unknown DNA. The incubation time for detection is ~3–5 min. The bio-composite platform also works successfully in a complex biomolecule matrix and cell lysate. However, the presence of serum albumin poses a hinderance in the serum sample. Particle size analysis proves that CPE displacement from GO surface by the incoming DNA is the reason for the ‘turn on’ response, and that the sensing process is exclusive to dsDNA. This new platform could be an exciting and rapid DNA sensing and characterization tool.
•Naturally fluorescent protein CPE studied with graphene oxide (GO) as quencher.•CPE-GO bio-composite showed full quenching, non-linear Stern Volmer kinetics.•CPE fluorescence regained only in presence of dsDNA.•Fluorescence regain linearly related to length (i.e. molecular weight) of DNA.•Bio-composite sensed and characterized DNA even in complex biomolecule sample.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A comprehensive, flexible approach and a generic framework for the construction of drive cycles.•A new definition of micro-trip to capture the stop-and-go driving behavior related emissions.•Time ...series shape based distances in the clustering process to retain real world transients.•The idea of a set of representative drive cycles for any region instead of one.
Building representative real world drive cycles is an important component in the modelling of emissions, battery health of electric vehicles and autonomous vehicles. All these applications are sensitive to the transients and diversity present in real world driving patterns, which are not adequately captured by current approaches. To address this lacuna, we use clustering techniques involving time-series (shape) based distances on the raw data directly to obtain representative sets of real world drive cycles. We demonstrate the efficacy of our approach using experimental data from a fleet of eight motorcycles run across five locations in India. Dynamic Time Warping (DTW) distance based clustering gives optimal results. We give theoretical and experimental justification for our constructions. We believe that the constructed drive cycles using the proposed approach would help in assessing the impact of various policies aimed at building eco-friendly transportation systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the past decade, eutrophication and phosphate recovery from surface water have become major issues. Adsorption is an effective method for phosphate removal because of its high efficiency. Even ...though lanthanum-based compounds are effective at removing phosphate from water, outside factors influence them. Hence, it is vital to develop and employ cost-effective innovations to fulfill ever-tougher requirements and address the issue of water contamination. Adsorption technology is highly effective in phosphate removal at concentrations from wastewater. This work briefly describes the preparation of lanthanum nano-adsorbents for the removal of phosphate efficiently in water, and phosphate adsorption on La-based adsorbents in various La forms. The work presented in this study offers an outline for future phosphate adsorption studies in La-based adsorbents, resulting in La-based materials with substantial adsorption capacity and strong regeneration capability.
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•Abiotic stresses are important tools for metabolites in microalgae.•Temperature, nutrient starvation, salinity and light influence PUFAs.•Nitrogen and light stress influence ...phycobiliproteins.•Salinity, light and nutrients influence carotenoids.
Microalgae, due to various environmental stresses, constantly tune their cellular mechanisms to cope with them. The accumulation of the stress metabolites is closely related to the changes occurring in their metabolic pathways. The biosynthesis of metabolites can be triggered by a number of abiotic stresses like temperature, salinity, UV- radiation and nutrient deprivation. Although, microalgae have been considered as an alternative sustainable source for nutraceutical products like pigments and omega-3 polyunsaturated fatty acids (PUFAs) to cater the requirement of emerging human population but inadequate biomass generation makes the process economically impractical. The stress metabolism for carotenoid regulation in green algae is a 2-step metabolism. There are a few major stresses which can influence the formation of phycobiliprotein in cyanobacteria. This review would primarily focus on the cellular level changes under stress conditions and their corresponding effects on lipids (including omega-3 PUFAs), pigments and polymers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In the velocity range outside the velocity-dynamic range of a PIV (particle image velocimetry) system, the velocity measurements are known to result in noisy velocity vectors due to erroneous ...detection of correlation peaks, especially in the low-velocity region. Here a simple method is proposed that uses two different timings of a pulsed laser, in conjunction with a median-test of residuals based on the velocity data, to resolve both low and high velocities in a flow field. This method detects the erroneous vectors and replaces them with the correct vectors via a comparison of two sets of PIV data, procured simultaneously with an appropriate time-delay. The validation of the proposed method is demonstrated via a comparison of the present experimental data with previous experiments and DNS (direct numerical simulations) of a round turbulent jet.•The method uses two-time intervals to resolve two sets of velocities such that each set falls within the dynamic range of PIV corresponding to the time interval. (Dynamic range heavily depends on time interval).•A quantity called normalised residual median is defined based on “universal outlier detector” which is used to consolidate the two sets of data.•The strength of the method lies in its ability to obtain instantaneous entrainment velocity even in an unsteady flow.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A transition mode between conduction and keyhole is utilized for defect free welding of Zr-2.5 wt.% Nb alloy.•Significant change in microstructural morphology across the different weld zones is ...observed.•The residual stress in fusion and heat affected zones is found to be tensile in nature compared to the base metal.•The hardness is found to be changed significantly across different weld zones as result of microstructural modification.•The tensile strength of as welded Zr-2.5 wt.Nb alloy is found to higher than the base metal with poor ductility.
In the present study, Zr-2.5 wt.%Nb alloy plates of thickness 4 mm have been welded using pulsed Nd:YAG laser system at different process parameters and characterized in terms of microstructural evolution, hardness, residual stress, and mechanical properties. It has been observed that heat input plays an important role on mode of welding. The full penetration up to a thickness of 4 mm of the alloy has been achieved at a minimum laser heat input of 800 J mm−1 without any crack and porosity formation. For avoiding the porosity formation in the weld zones, a transition mode between conduction and keyhole has been used by optimizing laser process parameters. The microstructural analysis revealed that the fusion (FZ) is consists of predominant lath type α′ martensitic phase with small amount of randomly distributed acicular type of α′ martensite phase. However, the heat affected zone (HAZ) have lath type α′ martensitic phase together with αZr phase. Further, in the FZ and HAZ regions, the presence of retained βZr phase is higher as compared to the base metal (BM). The change in microstructure and phase field of different weld zones has been explained by evaluating the time-temperature profiles and cooling rates using COMSOL multi-physics simulation. In addition, the FZ and HAZ zones have been found to have tensile residual stress of the order of 280 MPa and 145 MPa as compared to the BM (-70 MPa). The microhardness in the FZ region has been observed to be higher (240–260 HV0.1) as compared to the BM (∼185 HV0.1) due to the formation of martensitic phase. The tensile room temperature testing showed that the mechanical strength of as welded sample is significantly higher than the base metal with lower ductility. The fractography of the fractured surfaces confirmed ductile nature of failure in the as welded samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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