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Site Response Study and Amplification Factor for Shallow Bedrock Sites
No full textAmplification is a key paramter considered to account modifcation of seimic wave in the soil for earthquake resistance design of structure placed on soil. Initially, earthquake wave amplifications are related with shear wave velocity (Vs) ratio of soil and foundation layer, and then it was related to average value of Vs up to 30 m (Vs 30). Application of Vs 30 concept to represent amplification in shallow bedrock sites is questionable and has rock velocity added to soil velocity. In this study, shallow bedrock sites in Bengaluru, Chennai, Coimbatore and Vishakhapatnam has been analyzed to understand amplifications and its proximity to Vs 30. The site response calculations are done using one-dimensional nonlinear approach. Intraplate recordings from around the world suitable for the study area are selected. For comparison with known data, the amplification factors are evaluated considering the period ranges similar to international codes. Then, considering spectral signatures from response spectra for all site rock and surface motions, the factors are calculated for period range 0.01�0.06 s and 0.05�1.0 s. Based on the study, only one mid-period amplification factor has been proposed. This amplification factor represents the significant amplification of the site. Acceleration spectra show similar trends for different site classes irrespective of the fact that profiles are selected based on Vs values or SPT-N values. This is observed over a wide range of results and indicates shear modulus as an influencing parameter. Comparison of spectral signatures for different site classes suggests that amplification reduces as the modulus of the soil column increases. Thus, it may be appropriate to classify sites based on shear modulus of soil column
Numerical investigation of a conducting drop's interaction with a conducting liquid pool under an external electric field
No full textA charged conducting drop suspended in an insulating medium shows non-coalescence with an interface under high strength of an externally applied electric field. We perform numerical simulations of the non-coalescence phenomenon to understand the underlying physical mechanisms and the effect of electric field strength and fluid conductivity on the coalescence behavior of a conducting drop with a conducting liquid pool under highly viscous conditions. We show that two factors primarily govern the coalescence or non-coalescence of the drop with the interface. First, the magnitude of the charge transfer time scale (which governs the rate of charge transfer during contact between the drop and the pool) relative to the time scale of the capillary waves. Second, the strength of the electric forces compared to the viscous forces. We further show that for the case of macro drops (D�2 mm), charge transfer by fluid convection dominates charge conduction at lower electric conductivities (��10�8 S/m) only. Finally, we explain the non-dependence of secondary droplet's size and charge on the fluid's electric conductivity as observed in the experiments
Vinblastine production by the endophytic fungus Curvularia verruculosa from the leaves of Catharanthus roseus and its in vitro cytotoxicity against HeLa cell line
No full textThe current study was to isolate endophytic fungi producing high yields of indole alkaloids such as vinblastine analogous to their host Cathranthus roseus. Endophytic fungi were isolated from the leaves of C. roseus, identified as Curvularia verruculosa by molecular techniques, and the sequence was deposited in NCBI (MK995628). Vinblastine producing endophytic fungus was grown in 1L Vinca medium for 21 days. The extract was examined for vinblastine by chromatographic techniques. TLC plates showed purple colour spot co-migrated with authentic vinblastine and Rf was calculated by HPTLC (Vin 1 vinblastine �0.75; authentic vinblastine-0.78), these results confirmed vinblastine presence in the Vin1 extract. Further, the TLC purified fungal extract was examined by LC-MS, which revealed the exact mass of vinblastine (M + H+ m/z 811.51). The most important of the study is high yield production of vinblastine; hence, the extract analysed by HPLC revealed 182 μg/L vinblastine. The TLC purified fungal vinblastine was analysed for the cytotoxicity effect on HeLa cell line and it depicted a higher activity with IC50-8.5 μg/mL and apoptotic morphological changes were analysed. All the results revealed that the endophytic fungus Curvularia verruculosa produced vinblastine and for the first time in a surplus amount compared to other fungi
Polyakov-Mellin bootstrap for AdS loops
No full textWe consider holographic CFTs and study their large N expansion. We use Polyakov-Mellin bootstrap to extract the CFT data of all operators, including scalars, till O(1/N4). We add a contact term in Mellin space, which corresponds to an effective �4 theory in AdS and leads to anomalous dimensions for scalars at O(1/N2). Using this we fix O(1/N4) anomalous dimensions for double trace operators finding perfect agreement with 1 (for �� = 2). Our approach generalizes this to any dimensions and any value of conformal dimensions of external scalar field. In the second part of the paper, we compute the loop amplitude in AdS which corresponds to non-planar correlators of in CFT. More precisely, using CFT data at O(1/N4) we fix the AdS bubble diagram and the triangle diagram for the general case. © 2020, The Author(s)
Intraspecific differences in seed dispersal caused by differences in social rank and mediated by food availability
No full textWe use individual-based information on the behavior of wild female Japanese macaques in two consecutive years with different food availability (nut-rich vs. nut-poor) to test effects of dominance rank and nut fruiting on seed dispersal parameters. We predicted that social rank would affect dispersal (1) quantity, (2) quality, (3) species richness, and (4) percentage of berries in the diet in the nut-poor year, while these differences would disappear in the nut-rich year. We found seeds of nine fleshy-fruited plant species in the feces of the monkeys. The frequency of seed occurrence for two plant species (Viburnum dilatatum and Rosa multiflora) showed an interaction between dominance ranks and years; in the nut-poor year V. dilatatum seeds were more abundant among dominant females and R. multiflora among subordinates, while such inter-rank differences disappeared in the nut-rich year. Similarly, the intact ratio of V. dilatatum seeds was lower for dominants in the nut-poor year, while inter-rank variations disappeared in the nut-rich year. Finally, percentage of berries in diet and seed richness showed no inter-annual nor inter-rank variations. Our study highlights that differences in individuals� social rank lead to within-group variation in seed dispersal services and that these differences are dependent on nut availability
Novel biocatalyst for optimal biodiesel production from diatoms
No full textFatty acid methyl ester (biodiesel) has been derived from oil present in algae through transesterification using catalysts of acids, base, supercritical fluids, etc. These catalysts are corrosive and have been posing challenges of contaminating the environment necessitating environmentally friendly and biodegradable catalysts such as enzyme (lipase) based biocatalysts. In this study, fungal strains (endophytic/free spores) were isolated from an estuarine ecosystem and screened for extracellular lipase activities. A novel fungal strain Cladosporium tenuissimum, identified through molecular technique exhibited higher lipolytic activity among the isolates. The crude lipase extracted from fungus was subjected to ammonium sulphate precipitation and purification using Superdex 200 gel filtration chromatographic system. The molecular weight of purified lipase was found to be �46 KDa and a specific activity of 37.2 U/mg. Lipase activities attained stability and reached maximum at 60 °C temperature and pH of 6. The purified enzyme was used as a biological catalyst for enzymatic transesterification of oil obtained from an indigenously isolated salt tolerant diatom Nitzschia punctata. Spectroscopic analysis on fatty acids and Fatty Acid Methyl Esters derived from diatom exhibited similarities in specific functional groups between algal oil and biodiesel. Comparisons on biodiesel yield estimation and FAME compositions of enzyme catalyzed, acid catalyzed biodiesel assessed through gas chromatographic techniques revealed a higher efficiency (87.2 ± 0.47) of biocatalysts compared to conventional acid catalyst (83.02 ± 0.35) exhibiting potential scope for large scale application of environment friendly biocatalysts to enhance the conversion performances of the transesterification process
Generalized distributed state space model of a CSP plant for simulation and control applications: Single-phase flow validation
No full textConcentrating solar thermal power plants, also known as CSP plants, can be of different configurations depending on type of collectors, temperatures, heat transfer fluid, working fluid, and the thermodynamic cycle used in the plant. This leads to complex behavior with nonlinear dynamics, potential instability and parameters that vary in both space and time. In this work, a distributed state space model is proposed to ensure computational flexibility and facilitate industrial applications, such as optimization, control and automation. The format used allows the model to represent the thermal dynamics at different operation points including phase changes (liquid or gas) along the spatial dimension. To validate the model, some experimental tests have been made on an operating solar thermal plant located at the University of South Florida, in United States, where real input disturbances were applied to compare measurements with model predictions. Preliminary results show good agreement with experimental observations. Literature data of water and steam properties were used in the model, that can be easily extended to direct steam generation (DSG) plants
Synthesis, thermal stability and structural transition of cubic SnS nanoparticles
No full textRecently identified cubic polymorph of SnS (SnS-CUB) is a promising low-cost material for solar cell applications. We report on the thermal stability, structural and optical properties of SnS-CUB nanoparticles. The average crystallite size of cubic SnS nanoparticles synthesized by wet chemical method at 20 °C is about 34.9 nm and unit cell lattice parameter a = 11.59 à . We found that cubic phase remained structurally stable up to 400 °C even though sulfur is partially re-evaporated. The sample annealed at 450 °C contains both cubic and orthorhombic phases. When the annealing temperature is increased to 500 °C, the sample completely transforms to orthorhombic structure. Raman spectroscopy showed the formation of minor secondary phases Sn2S3 and SnO2 at temperatures �500 °C. Three distinct regions of weight loss are observed in thermogravimetric curve (TGA) of cubic SnS nanoparticles; around 300 °C, 600 °C and 800 °C. Weight loss of 10 observed near 600 °C was due to rapid re-evaporation of sulfur from SnS. Annealing at 500 °C decreases the direct optical bandgap value 1.68 eV�1.3 eV (direct), 1.0 eV (indirect) is also an indication of the structural transition of SnS-CUB to orthorhombic SnS. Cubic SnS nanoparticles were strongly absorbing light photons in the visible wavelength range of 400 nm�700 nm. The orthorhombic SnS with an indirect bandgap of 1 eV has extended the absorption edge to 1000 nm. By combining both cubic and orthorhombic SnS, the absorption can be extended to a wide wavelength range
Synthesis, crystal structure, optical, thermal, mechanical, dielectric and DFT studies of 3, 5-dimethylprazole:1,3,5-benzene tricarboxylic acid molecular adduct crystal
No full textAn organic molecular adduct, 3, 5-Dimethylpyrazole:1,3,5-benzene tricarboxylic acid was synthesized and single crystals grown in methanol-acetone (1:1) solvent mixture by slow solvent evaporation solution growth technique at room temperature. The formation of the molecular adduct and crystal structure have been confirmed by single crystal X-ray diffraction studies and NMR spectroscopic techniques. Further, the title crystal belongs to monoclinic crystal system with space group, P21/c and the supramolecular architecture of adduct involves extensive intermolecular O-H�N, N-H�O, O-H�O and C-H�O hydrogen bonding interactions. UV�Vis-NIR spectrum was recorded to find out the lower cut-off wavelength, percentage transmission and optical band gap energy. The fluorescence properties of the title crystal were identified by Photoluminescence spectral studies. Fourier transform infrared (FT-IR) spectral analysis was carried out to confirm the presence of various functional groups in the grown crystal. The quantum chemical analyses were performed by density functional theory (DFT) using B3LYP/6-311G (d,p) basis set. The thermal and mechanical properties of the grown crystal have been investigated by TG/DTA analyses and Vickers micro hardness measurement, respectively. The dielectric behaviours of title single crystal have also been investigated as a function of frequency at different temperatures
Bearing capacity of embedded foundations using quasi-kinematic limit analysis
No full textBearing capacity of rectangular foundations, with varying aspect ratios (1 <= L/B <= 5) and embedded at shallow to medium depths (D/B <= 5), has been evaluated by using the three-dimensional cell-based smoothed finite elements quasi-kinematic limit analysis. The results have also been obtained for circular and strip foundations by performing exclusively the axisymmetric and plane strain analyses. The associated optimization problem has been solved by employing the semidefinite programming (SDP). Shape factors (s(c), s(q) and s(gamma)) and depth factors (d(c), d(q) and d(gamma)) are given as a function of soil internal friction angle (phi). The shape factors have been expressed as a function of L/B, on the other hand, the depth factors have been given as a function of D/B and L/B. A thorough comparison of the results has been made with the different solutions available in literature. The variations of (i) power dissipation function, (ii) maximum plastic shear strain rates, and (iii) the nodal velocities patterns, have also been examined to interpret the failure mechanism