Simulated dynamics and thermodynamics processes leading to the rapid intensification of rare tropical cyclones over the North Indian Oceans

The life cycle dynamics and intensification processes of three long-duration tropical cyclones (TCs), viz., Fani (2019), Luban (2018), and Ockhi (2017) formed over the North Indian Ocean (NIO) have been investigated by developing a high-resolution (6 km × 6 km) mesoscale analysis using WRF and En3DVAR data assimilation system. The release of CAPE in nearly saturated middle-level relative humidity caused intense diabatic heating, leading to an increase in low-level convergence triggering rapid intensification (RI). The strengthening of the relative vorticity tendency terms was due to vertical stretching (TC Fani) and middle tropospheric advection (TCs Luban and Ockhi). The increase or decrease in upper-tropospheric divergence led to RI through two different mechanisms. The increase in upper divergence strengthens the vortical convection (in TC Luban and Fani) by enhancing the moisture and heat transport, whereas its decrease caused a reduction in the upper-level ventilation flow at 200 hPa followed by moisture accumulation, enhanced diabatic heating, and strengthened the warm core (TC Ockhi). The RI caused the vortex of three cyclones to extend up to the upper troposphere. The well organised wind during RI led the unorganised, weak, discontinuous vertical vortex columns to become organised with intense vertical velocity throughout the column. Spatial distributions of Okubo–Wiess (OW) parameter showed TC core dominated by vorticity than strain, since deep depression (DD) stages

GA-based multi-objective optimization of active nonlinear quarter car suspension system—PID and fuzzy logic control

Background The primary function of a suspension system is to isolate the vehicle body from road irregularities thus providing the ride comfort and to support the vehicle and provide stability. The suspension system has to perform conflicting requirements; hence, a passive suspension system is replaced by the active suspension system which can supply force to the system. Active suspension supplies energy to respond dynamically and achieve relative motion between body and wheel and thus improves the performance of suspension system. Methods This study presents modelling and control optimization of a nonlinear quarter car suspension system. A mathematical model of nonlinear quarter car is developed and simulated for control and optimization in Matlab/Simulink® environment. Class C road is selected as input road condition with the vehicle traveling at 80 kmph. Active control of the suspension system is achieved using FLC and PID control actions. Instead of guessing and or trial and error method, genetic algorithm (GA)-based optimization algorithm is implemented to tune PID parameters and FLC membership functions’ range and scaling factors. The optimization function is modeled as a multi-objective problem comprising of frequency weighted RMS seat acceleration, Vibration dose value (VDV), RMS suspension space, and RMS tyre deflection. ISO 2631-1 standard is adopted to assess the ride and health criterion. Results The nonlinear quarter model along with the controller is modeled and simulated and optimized in a Matlab/Simulink environment. It is observed that GA-optimized FLC gives better control as compared to PID and passive suspension system. Further simulations are validated on suspension system with seat and human model. Parameters under observation are frequency-weighted RMS head acceleration, VDV at the head, crest factor, and amplitude ratios at the head and upper torso (AR_h and AR_ut). Simulation results are presented in time and frequency domain. Conclusion Simulation results show that GA-based FLC and PID controller gives better ride comfort and health criterion by reducing RMS head acceleration, VDV at the head, CF, and AR_h and AR_ut over passive suspension system

Upper limit to the ultimate achievable emission wavelength in near-IR emitting cyclometalated iridium complexes

Iridium complexes bearing cyclometalated (C 27N) ligands are the current emitters of choice for efficient phosphorescent organic light emitting diodes (OLEDs). Homoleptic iridium complexes Ir(C 27N)3 and the analogous heteroleptic ones carrying a \u3b2-diketonate ancillary ligand (C 27N)2Ir(O 27O) often exhibit similar photophysical properties and device performances; the choice among them usually depends both on the yield/ease of the respective synthetic preparations as well as on the device fabrication methods (i.e. vacuum-deposition or solution-process). In our recent study we found a significant spectral red shift on going from the homoleptic to the \u3b2-diketonate Ir(iii) derivatives. The NIR emitting complex Ir(iqbt)2dpm (\u3bbmax = 710 nm) has almost 20 nm red shifted emission compared to the homologue Ir(iqbt)3 making only the former a real NIR emitter. For comparison, we studied the Pt(iqbt)dpm complex as the suitable example to investigate metal ligand interactions. Noteworthily the Pt(iqbt)dpm emission perfectly overlaps that of the Ir(iqbt)2dpm. In this paper we provide an in-depth investigation of these systems by electrochemical and spectroscopic analyses and corroborate the results with DFT and TDDFT calculations to investigate whether the Pt(ii) complex can be used as a model system to predict how far the emission can be pushed in a Ir(iii) heteroleptic derivative bearing the same C 27N ligand

RECONSTRUCTION OF TORN PAGE USING CORNER AND SEGMENT MATCHING

ABSTRACT: A challenging issue is to join the torn pieces of papers to reconstruct the original document. However this problem can be solved by using semi-automatic techniques. This can be a great advantage in forensic and investigation sciences. Torn pieces are joined by comparing edge length and and angles. Work is divided into three main stages foreground extraction, similarity feature extraction and merging process