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Seismic Hazard Assessment and Land Use Analysis of Mangalore City, Karnataka, India
No full textThis article presents a combined seismic risk assessment of Mangalore city, considering seismic hazard and Land Use (LU) patterns. Probabilistic seismic hazard analysis was carried out considering different source models and attenuation relations to predict Peak Ground Acceleration at every square kilometer. LU of the area was assessed using GIS tools with the built-in supervised Gaussian maximum likelihood algorithm on processed remote sensing data from temporal Landsat images. The risk map showed the concentration of built-up area South-West, toward the sea and the seismic hazard following an increasing trend from the coast to further inland
Highly ordered iron oxide-mesoporous fullerene nanocomposites for oxygen reduction reaction and supercapacitor applications
No full textIn this study, we report a facile synthetic strategy to embed ultra-small iron oxide nanoparticles within the channels of highly ordered mesoporous fullerene (C-60) (Fe-MFC60-T, where T denotes the temperature of the template synthesis). The present work is judicially designed to form the hematite phase of iron oxide (alpha-Fe2O3) nanoparticles (NPs) through the subsequent calcination of Fe-MFC60-T. The Fe-MFC60-T materials were analysed comprehensively for obtaining their physico-chemical properties. Among the materials studied, Fe-MFC60-150 exhibits a unique doughnut-shaped morphology with a high specific surface area ( 598 m(2) g(-1)), crystalline wall structure, and well-ordered porosity. The Fe-MFC60-150 displays an adequate oxygen reduction reaction (ORR) activity with a positive onset potential at 0.85 V (vs RHE) and half wave potential at 0.78 V (vs RHE), low Tafel slope (66 mV per decade), high exchange current density (1.2 x 10(-10) A cm(-2)), and good tolerance towards methanol crossover. We also demonstrate that Fe-MFC60-150 is capable of delivering a specific capacitance of 112.4 F g(-1) at 0.1 A g(-1). The electrochemical performance of Fe-MFC60-150 towards ORR and super capacitor can be ascribed to the synergistic coupling effects between the active sites of alpha-Fe2O3 and MFC60
Evaluation of magnetic nanoparticle of irinotecan for personalized treatment of colorectal cancer
No full textA simple technique for direct, high power laser beam profile measurement using thermal imagers
No full textMeasuring the profile of a laser beam is of critical importance, especially for high power laser systems. Although different techniques exist to measure the beam profile, owing to the use of optoelectronic detectors or cameras, they primarily work at lower powers and require tapping and attenuating the beam. In this process, there is potential for the diagnostic system affecting the beam quality. In this work, we propose a simple technique which can measure the beam profile at full power using a thermal imager without the need for additional optical components. The method involves taking a thermal image of the beam while it is incident on an absorptive surface such as a thermopile head which is used to measure optical power. In addition, a second image is taken using a focused incidence on the surface at low powers. The second image which is reused provides the point spread function. We then make use of the linearity of the heat equation which allows the deconvolution of the point spread function from the original image to obtain the actual beam profile. In this work, we utilized the technique to directly analyze the beam profile at full power of a 100 W class fiber laser and analyzed deviations from single-modedness. In addition, we utilized offset splices to few-mode fibers to launch higher order modes at the 100W level and demonstrate their direct characterization of multimode nature of the profile. This technique provides a simple alternative, using instruments present in most laser labs for direct, high power laser beam profiling
Studies on die filling of A356 Al alloy and development of a steering knuckle component using rheo pressure die casting system
No full textIn this study, a computational fluid dynamics (CFD) model is developed to investigate die filling of semi solid slurry as part of rheo pressure die casting (RPDC) system. The die filling cavity corresponds to that of an automobile steering knuckle, and the slurry is made of A356 aluminium alloy. The rheological model used in the CFD simulation is determined experimentally. The results obtained from present numerical model includes flow field of the slurry within the die cavity, viscosity evolution, solid fraction distribution, temperature and pressure distribution during solidification within cavity during die filling stage. The main objective of the study is to determine the gating arrangement, pouring temperature, and injection conditions for desirable microstructure and mechanical properties of the developed component. To study the effect of injection conditions on die filling capability of the said alloy slurry, five injection profiles are studied, with a variation in final injection velocity between 2-3.2 m/s. In order to corroborate the findings of the present study, microstructural morphology and structure-property correlation have been studied, primarily in the form of optical microscopy and macro hardness measurements, by obtaining samples from different locations of the solidified component
Pathways of electron transfer and proton translocation in the action of superoxide dismutase dimer
No full textSuperoxide dismutase, known to gain large rate enhancement on dimerization, forms a homodimer stabilized by hydrogen bonding between a number of internal water molecules and a few amino acid residues at the interface. Within each subunit the beta-sheets provide a sequence of delocalized pi-electron units of peptide bonds alternating with hydrogen bonds referred as pi-H pathway. These pathways in the two subunits in the dimer are interlinked through a chain of four water molecules bridged by hydrogen bonds at the interface. Connecting the two Cu-centers this pi-H pathway can enable rapid electron transfer from one superoxide molecule to the other, crucial for the catalytic reaction and the high rate in the dimer. A proton relay of hydrogen-bonded water molecules in the dimer translocates protons to form the product, hydrogen peroxide. (C) 2019 Elsevier Inc. All rights reserved
A Global Analysis of Land Surface Temperature Diurnal Cycle Using MODIS Observations
No full textDiurnal variations of land surface temperature (LST) play a vital role in a wide range of applications such as climate change assessment, land-atmosphere interactions, and heat-related health issues in urban regions. This study uses 15 years (2003-17) of daily observations of LST Collection 6 from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board the Aqua and the Terra satellites. A spline interpolation method is used to estimate half-hourly global LST from the MODIS measurements. A preliminary assessment of interpolated LST with hourly ground-based observations over selected stations of North America shows bias and an error of less than 1 K. Results suggest that the present interpolation method is capable of capturing the diurnal variations of LST reasonably well for different land-cover types. The diurnal cycle of LST and time of occurrence of maximum temperature are computed from the spatially and temporally consistent interpolated diurnal LST data at a global scale. Regions with higher variability in the timing of maximum LST hours and diurnal amplitude are identified in this study. The global desert regions show generally small variability of the monthly mean diurnal LST range, whereas larger areas of the global land exhibit rather higher variability in the diurnal LST range during the study period. Moreover, the changes in diurnal temperature range for the study period are examined for distinct land-cover types. Analysis of the 15-yr time series of the diurnal LST record shows an overall decrease of 0.5 K in amplitude over the Northern Hemisphere. However, the diurnal LST range shows variant changes in the Southern Hemisphere
Peak-to-Average Power Ratio of OTFS Modulation
No full textIn this letter, we analyze the peak-to-average power ratio (PAPR) of orthogonal time frequency space modulation (OTFS) waveform. Towards this, we consider modulation symbols on an N x M delay-Doppler grid, where N and M are the number of Doppler and delay bins, respectively. We derive an upper bound on the PAPR of the OTFS signal and show that the maximum PAPR grows linearly with N (and not with M, the number of subcarriers, as observed in conventional multicarrier schemes such as OFDM). We analytically characterize the complementary cumulative distribution function (CCDF) of the PAPR of OTFS with rectangular pulse for large values of N. We present the simulated CCDF of the PAPR of OTFS for different pulse shapes and compare it with those of OFDM and generalized frequency division multiplexing (GFDM). It is shown that OTFS can have better PAPR compared to OFDM and GFDM
Weibull and Generalized Extreme Value Distributions for Wind Speed Data Analysis of Some Locations in India
No full textWind velocity data modeling plays a crucial role for the estimation of wind load and wind energy. Apart from these, the same modeling must also be used in the load cycle analysis of fatigue failure in slender structures to address periodic vortex shedding. Most authors fitted the entire available range of wind velocities of various locations using Weibull models. However, they did not check the validity of the model in describing the range of extreme wind velocity. In this work, the validity of Weibull models for describing parent as well as extreme hourly mean wind velocity data for four places on the east coast of India has been checked. While it predicts lower wind speeds accurately, the Weibull model has been found to become inappropriate for describing wind velocity in the range of extremes, i.e., above a certain threshold value. Therefore, this article focuses on the techniques of determining a limiting wind velocity beyond which the Weibull distribution is rendered unsuitable. In the range where the Weibull distribution fails, various extreme value distributions, such as Gumbel, Frechet and reverse Weibull distributions have been compared, thereby determining the best estimator for each location
Seismic magnitude conversion and its effect on seismic hazard analysis
No full textThe aim of this study is to demonstrate the bias created in the seismic hazard studies due to the choice of magnitude scaling equations without any statistical basis. The earthquake catalogue of Tripura, India, has been used for the purpose of this study. The catalogue was homogenized using the various scaling equations suitable for the region. Then, the bias created on parameters, like the magnitude of completeness (M-c), a and b values of the Gutenberg-Richter recurrence relation, maximum magnitude (M-max), and peak ground acceleration, was demonstrated. The standard deviations of M-c, a, and b parameters were observed to be 0.23, 0.27, and 0.037 respectively. The maximum variations in the M-max and ground motion estimates were found to be 0.7 magnitude units and 0.2g respectively. Then, the robustness of the regional rupture characters in overcoming the observed variations has been demonstrated. The trend of the rupture behavior of the seismic sources seems to be unaffected by the change in the magnitude scaling equations. The M-max calculated from the rupture-based procedure was observed to be higher than that calculated from the probabilistic method. This variation in M-max estimation has been utilized to critically assess the suitability of the magnitude scaling equations for the particular study area