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Predictive Control Based Constant Current Injection Scheme for Characterization of Switched Reluctance Machine
No full textA novel constant current injection-based characterization scheme for the switched reluctance machine (SRM) is proposed here. Unlike conventional characterization methods where the rotor is locked at a fixed position, the current injection-based method maintains the phase current constant while the machine runs at constant speed. A novel current controller, required for the proposed constant current injection scheme, is also proposed in this paper. The predictive control-based current controller works without the machine model being available. The proposed current controller is validated experimentally and is then used to characterize a 4 kW, 1500 r/min 8/6 pole SRM. The characteristics obtained are found to be in good agreement with those obtained using conventional locked rotor tests
Salmonella escapes antigen presentation through K63 ubiquitination mediated endosomal proteolysis of MHC II via modulation of endosomal acidification in dendritic cells
No full textCD4(+) T-cell response is vital for successful clearance of Salmonella Typhimurium infection. Efficient antigen presentation is crucial for effective CD4(+) T-cell response. Previous study has reported that Salmonella abrogates antigen presentation capacity of dendritic cells in order to escape host adaptive immune response. In this study, we have elucidated the mechanism of Salmonella-mediated downregulation of the total cellular Major Histocompatibility Complex (MHC) II pool in dendritic cells. Infected dendritic cells show upregulation of E3 ubiquitin ligase, MARCH1 expression and K63-linked ubiquitination of MHC II. Salmonella infection also enhances the internalisation of ubiquitin-tagged MHC II molecules that are subsequently degraded by endosomal proteases. In addition, Salmonella regulates the activation of endosomal proteases by lowering the pH of endosomes. In infected dendritic cells, Salmonella delays NOX2 recruitment to the phagosomes thereby preventing its alkalinisation. NOX2 is a significant part of innate immune response against pathogens as it is responsible for Reactive Oxygen Species (ROS) production. In this study, we have demonstrated how Salmonella evades MHC II-mediated adaptive immune response in dendritic cells through enhanced endosomal proteolysis. To escape host CD4 + T response, Salmonella delays NOX2 recruitment, an innate immune response element to the phagosomes
Active Vibration Suppression of Nonlinear Cantilever Beam using Shape Memory Alloy Actuators
No full textThis paper presents the active vibration suppression of a cantilever beam using shape memory alloy (SMA) wires as actuator. The cantilever beam is modelled as a nonlinear distributed parameter system (DPS) following the Euler Bernoulli Beam theory. Sensors and actuators are optimally placed at discrete locations along the cantilever beam. Controllability Gramians are evaluated to determine the optimal locations for the actuator placement. Modal analysis is used to determine the optimal locations for the sensor placement. The desired system response is obtained by designing a nonlinear controller using the concepts of dynamic inversion and optimal control. This methodology is based on the Design Then Approximate (DTA) philosophy. Optimal Dynamic Inversion is used as the control technique to ensure suppression of vibration along the length of the beam. This approach of control design can be used for any randomly generated initial profile of the beam. Experimental setup is designed using discrete sensors such as LASER sensor and Piezoelectric Sensor and the actuation is done using SMA based wire actuators. The control algorithm is verified experimentally and theoretically for vibration suppression. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved
Bounds for the Petersson norms of the pullbacks of Saito-Kurokawa lifts
No full textUsing the amplification technique, we prove that `mass' of the pullback of the Saito-Kurokawa lift of a Hecke eigen form g is an element of S-2k is bounded by k(1-1/210+epsilon). This improves the previously known bound k for this quantity. (C) 2018 Elsevier Inc. All rights reserved
Effects of alloying addition on deformation mechanisms, microstructure, texture and mechanical properties in Fe-12Mn-0.5C austenitic steel
No full textIn the present investigation, the dependence of deformation mechanisms on quaternary alloying addition has been investigated for medium Mn austenitic steel. A steel with composition Fe-12Mn-0.5C-X (X: Ni and Al), a medium Mn austenite steel was deformed up to 60% by cold reduction to investigate the deformation mechanisms and texture evolution. Electron Back-scattered Diffraction (EBSD) and X-ray bulk texture measurement have been performed to study the deformation behaviour. Deformed microstructure with increasing strain was systematically analyzed with respect to the alloying addition. SFE of the alloy can be tailored by the addition of alloying elements. In the present investigation, SFE has been tailored by addition of Carbon, Aluminium and Nickel. The highest deformation twin fraction has been observed in Ni added sample and the lowest in the Al added sample. Visco plastic self-consistent (VPSC) simulation has been performed to understand the contribution of slip and twin activity during deformation
An Integrated Rural Development Model based on Comprehensive Life-Cycle Assessment (LCA) of Khadi-Handloom Industry in Rural India
No full textKhadi is an indigenous handloom industry of India which has an imperative legacy attached with the Indian Freedom Movement.. Khadi means any fabric which is hand-woven using a spinning wheel called `Charkha'. In the pre-industrialized era, Kltadi was one of the most prominent indigenous fabrics, which promoted self-reliance and self-sufficiency in the rural areas. But post-independent India experienced a sudden upsurge in technology-intensive, urban textile mills. This paper studies the Lite-Cycle stages of production of Khadi-handloom fabrics, through a comprehensive life-cycle assessment (LCA) performed using GaBi software; to assess its energy consumption and environmental impacts. It was observed that production of Khadi-handloom fabric is environmentally sustainable and socially more inclusive as compared to mass-produced textiles, Furthermore, socio-economic and cultural dimensions were added as an extension to LCA to fornmlate an integrated Khadi-based rural development model. The proposed model provides an alternative paradigm for local community-based sustainable rural development. (C) 2018 The Authors. Published by Elsevier B.V
PlaneFinder: a methodology to find the best plane for a set of atoms involved in the metal coordination in protein structures
No full textMetal ions play a considerable role in protein structure and function. The roles of most metals and their importance are determined by the arrangements of the interacting atoms in the three-dimensional protein structure. This information is essential in predicting the geometry of the atoms involved in metal coordination. The deviation of the other atoms from the best plane is another crucial factor. The proposed web server, PlaneFinder, provides a fast and efficient method to calculate the best-fit plane for a set of atoms involved in the metal coordination. It provides in addition other possible planes by considering the maximum number of interacting atoms as well as user-selected atoms. The deviations of the selected atoms and other atoms from the best-fit plane are also displayed. PlaneFinder is freely available and can be accessed at http://bioserverl.physics. iisc.ac.in/plane/
Ultrafast Raman Loss Spectroscopy Unravels the Dynamics in Entangled Singlet and Triplet States in Thioxanthone
No full textThioxanthone (TX), an aromatic ketone, exhibits significant solvent-dependent photophysical properties. Herein, we employed timeresolved ultrafast Raman loss spectroscopy (URLS) to decipher the solventdependent structural dynamics in entangled singlet and triplet states of photoexcited TX. The evolution of the vibrational spectrum reveals structural changes that occur during the intersystem-crossing (ISC) process and the subsequent energy dissipation to the surrounding solvent. The C=0 stretch (similar to 1320 cm(-1)) of TX in the excited state acts as the marker band as it undergoes a red shift with time constants of similar to 45 and similar to 5 ps in acetonitrile and methanol, respectively. Such a red shift is an indicator of the softening of the bond due to the change in the electronic spin states. We also observed a blue shift in Raman frequencies corresponding to the C=C stretch and the C=0 stretching modes of TX in acetonitrile and methanol, indicating vibrational cooling in the excited singlet and triplet states. In the case of TX in cyclohexane, vibrational modes at 190 and 415 cm(-1) exhibit a blue shift with a time constant of similar to 700 fs, which represents the structural distortion during internal conversion (S-2 -> S-1) process. The kinetics of amplitudes of these modes follows biexponential growth with time constants of similar to 3 and similar to 14 ps representing the time scales for the ISC process and the planarization process in the triplet state, respectively. The URLS study therefore provides a direct measure of the various stages of the solvent-dependent structural dynamics in the excited state of TX
TDOA-Based Multiple Acoustic Source Localization Without Association Ambiguity
No full textMultiple source localization using time-differences of arrival (TDOAs ) is challenging because of the ambiguity involved in associating the TDOAs computed across microphone pairs to the sources. We show that the association ambiguity of the TDOAs can be effectively resolved using the concept of an inverse delay interval region (IDIR), which we introduce in this paper. By examining the association between a spatial domain and the TDOAs, we define IDIR as an interhyperboloidal spatial region corresponding to an interval of delays for a given pair of microphones. The proposed scheme for localizing multiple sources involves two stages. In the first stage, the given enclosure is partitioned into nonoverlapping elemental regions and the ones that contain a source are detected using a measure based on the generalized cross-correlation with phase transform and the IDIRs. In the second stage, the sources are finely localized within each of the detected elemental regions by identifying the IDIRs containing a single source and a novel region-constrained localization approach. We evaluate the performance of the proposed approach on real recordings from the AV16.3 corpus and in a simulated reverberation setting with a reverberation time RT60 of up to 500 ms, and show that the DOA estimation error with two active speakers is within 2 degrees and the spatial localization error is less than 30 cm for each speaker
Wafer-scale synthesis of a uniform film of few-layer MoS2 on GaN for 2D heterojunction ultraviolet photodetector
No full textLayered transition metal dichalcogenide materials grown over a conventional 3D semiconductor substrate have ignited a spark of interest in the electronics industry. The integration of these 2D layered materials extensively addresses the formidable challenges faced by a new generation of opto-electronic and photovoltaic devices. Herein, we have demonstrated a 2D/3D heterojunction type photodetector by depositing MoS2 on a GaN substrate with a mass-scalable sputtering method. Spectroscopic and microscopic characterizations expose the signature of the highly crystalline, homogeneous and controlled growth of a deposited few-layer MoS2 film. The greater light absorption of few-layer MoS2 results in the high performance of the MoS2/GaN photodetector. Our device shows high external spectral responsivity (similar to 10(3) A W-1) and detectivity (similar to 10(11) Jones) with a very fast response time (similar to 5ms). Our obtained results are significantly better than previous MoS2- and GaN-based photodetectors. This work unveils a new perspective in MoS2/GaN heterojunctions for high-performance optoelectronic applications