Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

In the last few years, there has been extensive research in the design and fabrication of tandem solar cells. To analyse the transport in these devices and to optimize the device structure for enhanced response, simulation of these device configurations are crucial. In our work, we simulate the optoelectronic behaviour of a perovskite-silicon multi-junction tandem solar cell with a silicon tunnel junction, by accounting for different optical losses at the interface of each layer and by taking into account the limits of different recombination mechanisms (radiative and non-radiative). We have used a simple TCAD-based approach to understand and model the different transport mechanisms and losses in a perovskite-silicon tandem solar cell. We have compared simulated characteristics with corresponding measured characteristics from an experimental device. © 2020 IEEE.

World University root node

Department of Electrical Engineering

2020 5th IEEE International Conference on Emerging Electronics, ICEE 2020

Modeling of Perovskite-Silicon Tandem Solar Cells: A TCAD-based Approach

Transition metal dichalcogenide (TMD) memris-tors with vertical transport and atomic scale inter-electrode distances have recently been reported. These devices demonstrate bipolar switching characteristics, with relatively low switching voltages. With multiple input sweeps, variability in switching behaviour is also seen. Our work models the transport in vertical TMD memristors, with a focus on explaining the current-voltage (I-V) characteristics and the associated variability, by analysing different current components. © 2020 IEEE.

Proceedings of the IEEE Conference on Nanotechnology

Modeling of electrochemical metallization-based transport in vertical transition metal dichalcogenide (TMD) memristors

This paper presents a novel linear to cross reflective type polarization converter for X and Ku-band applications. It comprises a 45° tilted resonating patch on the top of a thin FR-4 substrate, which is terminated by PEC on the other side. The converter exhibits Polarization Conversion Ratio (PCR) greater than 90% over 10.17 GHz bandwidth (from 8.2 to 18.37 GHz ) with 76.5% fractional bandwidth (FBW). Multiple surface plasmonic resonances are responsible for uniform PCR over the broadband. The reason behind the ideal response at resonant frequencies is illustrated by surface current distribution analysis. This design is obliquely stable up to 30°, with a minimum of 87% PCR, for the transverse electric (TE) mode and the same is observed for transverse magnetic (TM) case. The proposed linear-cross converter is compact with periodicity 0.213λL and thickness 0.07λL, where λL corresponding to the free-space wavelength of lowest bandwidth frequency. RCS analysis has been performed for monostatic and bistatic cases to demonstrate the capability of the proposed design in EM shielding applications. © 2020 IEEE.

Proceedings of the 2020 International Symposium on Antennas and Propagation, APSYM 2020

Broadband Linear-Cross Reflective type Polarization Converter for X and Ku-band Applications

This work presents a single-layered broadband polarization-insensitive circuit analog absorber for X to K-band applications. The design is made of a circular ring resonator loaded with four lumped resistors and a circular-split cross dipole, printed on the top of a dielectric substrate terminated with the ground. In the azimuthal plane, the proposed structure is insensitive to different polarization angles of the electric field due to the four-fold symmetry, and it also demonstrates a stable absorptivity up to 45° for both Transverse Electric (TE) and Transverse Magnetic (TM) incidences in the elevation plane. Multiple plasmonic resonances are responsible for the broadband behaviour, and the ohmic losses in lumped elements are the reason for near-unity absorption over the broadband. The response of the proposed equivalent transmission line model is validated with the full-wave analysis up to a reasonable extent. To the best of authors knowledge, this design is angular stable absorbing metasurface operational with limited chip resistors over broadband without compromising the performances, and it is suitable for the applications like Radar Cross Section (RCS) reduction and RF energy harvesting. © 2020 IEEE.

Broadband Polarization Insensitive Angular Stable Cross Dipole Loaded Circular Ring Circuit Analog Absorber (CAA) for X to K-Band Applications

A dual band monopole resonator antenna is proposed in this paper. The antenna works at two different bands with central frequencies of 2.4 GHz and 5 GHz. To cover the two bands of WLAN (i.e., lower band of 2.4 GHz and upper bands of 5 GHz), two monopoles are used: one working for the lower band and the other working for the higher band. However, there is a limit in most of these antennas to obtain the wideband characteristic especially at the 5-GHz band for WLAN applications, when operating simultaneously at 2.4 GHz. The proposed antenna achieves a good bandwidth at the upper frequency, the data rate has been increased with the help of MIMO configuration. The simulated results are giving a very good return loss of -22.14 dB for 2.4 GHz band and -35.43 dB for 5.0 GHz for the single antenna. © 2020 IEEE.

IEMTRONICS 2020 - International IOT, Electronics and Mechatronics Conference, Proceedings

Dual band monopole antenna for WLAN MIMO applications at 2.4 and 5 GHz

Active control of noise for multi-channel applications is affected by the existence of nonlinear primary and secondary paths. There is a degradation in the performance of linear multi-channel active noise control (LMANC) systems based on minimization of sum of squared errors obtained from multiple sensors in presence of nonlinear primary path (NPP) and nonlinear secondary path (NSP) conditions. The NPP and NSP problems are more prominent and challenging for multi-point noise control applications owing to different locations of silent zones and acoustic coupling between secondary sources and error sensors. In order to surmount this problem, an incremental strategy based nonlinear distributed ANC (NDANC) system is developed in this article. The adaptive exponential functional link network (AE-FLN) is employed as an adaptive control unit at the acoustic sensor nodes (ASNs) for the design of NDANC system. The incremental co-operation scheme is utilized to provide uniform noise cancellation in presence of NPP and NSP conditions. Simulation study is conducted extensively to demonstrate the efficiency of the proposed system for different practical NPP and NSP scenarios. The detailed computational load analysis and subjective evaluation of reduction in perceptual noise levels are performed for different real noise conditions. Copyright © 2020 IEEE.

IEEE Open Journal of Signal Processing

Incremental learning based adaptive filter for nonlinear distributed active noise control system

In this article, we propose a new on-device photoplethysmography (PPG) signal quality assessment (SQA) system based on the first-order (FO) predictor coefficient (PC) of differenced sensor (DS) signal that is capable of significantly reducing false alarms and timely notifying sensor disconnection and saturation in unsupervised health monitoring. The proposed system consists of the DS signal computation, random noise addition, PC estimation, and hierarchical decision rules. The proposed system is evaluated by using varieties of sensor signals taken from standard databases and the PPG signals recorded using three PPG sensing modules available at our Biomedical System Laboratory. Results show that the proposed method achieves correct detection rates of 98.22\%, 80.09\%, and 99.79\% for noise-free PPG segments, motion artifacts corrupted segments, and pulse-free segments, respectively, and also outperforms other SQA methods. The proposed method had a false alarm reduction rate of 90.71\% and a missed acceptable quality rate of 1.78\%. Real-time implementation on the Arduino Due computing platform with a 32-bit Cortex-M3 processor, 512-kB flash memory, and 96-kB data memory demonstrates that the proposed on-device SQA system consumes 0.141 mJ with an overall accuracy of 93.21\%, whereas the kurtosis and Shannon entropy (KSE) and the fiducial and template (FT)-based methods consume 109.08 and 6.71 mJ with overall accuracies of 39.24\% and 74.13\%, respectively. The proposed system has great potential for developing energy-efficient accurate and reliable Internet of Things (IoT) and smartphone-based health monitoring systems.

IEEE Transactions on Instrumentation and Measurement

On-device integrated ppg quality assessment and sensor disconnection/saturation detection system for IoT health monitoring

During the last week of December 2019, Wuhan (China) was confronted with the first case of respiratory tract disease 2019 (coronavirus disease 2019, COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the rapid outbreak of the transmission (~3.64 million positive cases and high mortality as of 5 May 2020), the world is looking for immediate and better therapeutic options. Still, much information is not known, including origin of the disease, complete genomic characterization, mechanism of transmission dynamics, extent of spread, possible genetic predisposition, clinical and biological diagnosis, complete details of disease-induced pathogenicity, and possible therapeutic options. Although several known drugs are already under clinical evaluation with many in repositioning strategies, much attention has been paid to the aminoquinoline derivates, chloroquine (CQ) and hydroxychloroquine (HCQ). These molecules are known regulators of endosomes/lysosomes, which are subcellular organelles central to autophagy processes. By elevating the pH of acidic endosomes/lysosomes, CQ/HCQ inhibit the autophagic process. In this short perspective, we discuss the roles of CQ/HCQ in the treatment of COVID-19 patients and propose new ways of possible treatment for SARS-CoV-2 infection based on the molecules that selectivity target autophagy.Abbreviation: ACE2: angiotensin I converting enzyme 2; CoV: coronavirus; CQ: chloroquine; ER: endoplasmic reticulum; HCQ: hydroxychloroquine; MERS-CoV: Middle East respiratory syndrome coronavirus; SARS-CoV: severe acute respiratory syndrome coronavirus; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2. © 2020 Informa UK Limited, trading as Taylor & Francis Group.

Biological Sciences and Engineering

Autophagy

Autophagy as an emerging target for COVID-19: lessons from an old friend, chloroquine

In humans, loss-of-function mutation in the Signal Transducer and Activator of Transcription 3 (STAT3) gene is frequently associated with susceptibility to bacterial as well as fungal infections including aspergillosis, although its pathogenesis remains largely unknown. In the present study, we investigated the immune responses obtained after stimulation with Aspergillus fumigatus in STAT3-deficient patients. A. fumigatus conidial killing efficiencies of both monocytes and neutrophils isolated from whole blood samples of STAT3-deficient patients were not different compared to those of healthy controls. After stimulation with A. fumigatus conidia, lower concentrations of adaptive cytokines (IFN-γ, IL-17 and IL-22) were secreted by peripheral blood mononuclear cells from STAT3-deficient patients compared to those from healthy controls. Moreover, the frequency of IFN-γ and IL-17 producing CD4+ T cells was lower in STAT3-deficient patients vs. healthy controls. Among the STAT3-deficient patients, those with aspergillosis showed further lower secretion of IFN-γ upon stimulation of their PBMCs with A. fumigatus conidia compared to the patients without aspergillosis. Together, our study indicated that STAT3-deficiency leads to a defective adaptive immune response against A. fumigatus infection, particularly with a lower IFN-γ and IL-17 responses in those with aspergillosis, suggesting potential therapeutic benefit of recombinant IFN-γ in STAT3-deficient patients with aspergillosis. © Copyright © 2020 Danion, Aimanianda, Bayry, Duréault, Wong, Bougnoux, Tcherakian, Alyanakian, Guegan, Puel, Picard, Lortholary, Lanternier and Latgé.