Search

A proposed core–shell gate all-around junctionless field-effect transistor (CS GAA JLFET) is studied using extensive simulations. An oppositely doped core is sandwiched between the shells to achiev...

Wide band gap semiconductors such as ZnO are characterized by unique optoelectronic properties, which have led to numerous applications in the field of sensors and optoelectronics. These components...

This paper presents analytical analysis for a linearization method of a microwave photonic (MWP) link based on dual-drive dual-parallel Mach–Zehnder Modulator. Electric phase shifters are utilized to suppress intermodulation distortion terms and to further increase linearity of the link. A simulation model is designed to evaluate spurious free dynamic range (SFDR) against third order intermodulation distortion as it is a key performance measurement parameter of MWP link. A suppression of 68 dB is found in intermodulation terms and SFDR enhances by 16 dB which ensures the improvement in performance of link against intermodulation terms.

A 3–12 GHz ultra-wideband (UWB) low noise amplifier (LNA) is proposed in this paper. The first stage common-gate (CG), common-source (CS) noise canceling approach is used to achieve low noise-figure (NF). CG configuration at the input stage provides wideband input-matching. The noise of CG transistor is cancelled by systematically added two parallel CS transistors, whose outputs are cascoded in second stage. In order to achieve flat power gain (S21) response, a series peaking inductor is used in the second stage. The proposed LNA is designed in 90 nm CMOS process with chip-layout area of 0.467 mm2 and in comparison to the existing LNAs, it consumes a low power of 5.7 mW from a 1 V supply. The achieved input-reflection coefficient (S11) is 22) is S21 of 20.84 ± 0.28 dB over 4.2–10 GHz, with NF ranging from 2.6–3.6 dB.

In the present work, we studied the down conversion luminescence behavior of Er3+ substituted Sr0.7Bi2.2Nb2O9 bismuth layered ceramics (SBN-xEr, x = 0.0, 0.6, 0.8, 1) prepared by improved s...

A scheme to suppress nonlinear intermodulation distortion in microwave photonic (MWP) link is proposed by using polarizers to compensate inherent non-linear behavior of dual-electrode Mach-Zehnder modulator (DE-MZM). Insertion losses and extinction ratio have also been considered. Simulation results depict that spurious free dynamic range (SFDR) of proposed link reaches to 130.743 dB.Hz2/3. A suppression of 41 dB in third order intermodulation distortions and an improvement of 15.3 dB is reported when compared with the conventional link. In addition, an electrical spectrum at different polarization angles is extracted and 79 ∘ 79^\circ is found to be optimum value of polarization angle.

Increasing population pressure and decreasing cultivable land brought the agricultural sector at an alarming situation of food production particularly in the developing countries. To feed the burgeoning population, the agriculture sector needs to become more productive and diversified while facing the adversity of climate change and limitations of natural resources. During 1960–70, the improved irrigation facilities, the use of fertilizers and pesticides in the cultivation of high yielding varieties of cereals successfully led to the Green revolution in India. In the present scenario, the low irrigation and fertilizer use efficiencies, poor pesticide application and delivery are amongst the important issues in developing countries that need to be addressed for getting higher productivity. Also, fertilizer and pesticide usage also had severe associated environmental consequences like eutrophication, resistance and resurgence in pest, toxicity to non-target organisms, residues in food and feed, accumulation in the environment, etc. In such conditions, organic farming, a traditional practice coupled with the exploration of bio-nanoparticles to achieve a sustainable production system seems to be a better option. This review focuses on current research developments in the areas of bio-nano-enabled crop nutrition, protection, post-harvest management, and the possibility of bio-nanomaterials and organic farming confluence to revolutionize the agricultural sector by ensuring sustainable food security for coming generations.

A linearization scheme is proposed for microwave photonic link to enlarge spurious free dynamic range using a dual-electrode dual parallel Mach–Zehnder modulator (MZM). This scheme employs phase control method to improve performance of the link by adjusting phase of radio frequency (RF) signals and bias voltages of optical modulator. Optical single sideband modulation is achieved through sub-modulators of dual parallel MZM which increases efficiency of the link. The simulated results show that third order intermodulation distortion is suppressed by 28 dB when the input RF signals are 9.1 and 9.5 GHz and noise floor is at −161 dBm/Hz. The spurious free dynamic range is also improved by 12.6 dB.

In this work, intrinsic and doped TiO2 nanoparticles with different Palladium (Pd) concentrations were successfully synthesized via solvothermal method. The structural, morphological and optical properties of the as-synthesized nanoparticles are investigated. Photodiode properties of the as-synthesized nanoparticles based spin coated films are also investigated. A p-n and p-i-n heterojunction structures are fabricated on ITO coated glass and studied for small (± 5 V) bias voltage. From the IV characterization, responsivity, sensitivity, external quantum efficiency and switch current ratio is evaluated for both the heterostructures. Results showed that the proposed p-i-n photodiode attain good stability and quick response as compared to the conventional p-n photodiode. Hall measurement confirmed that heavily Pd doped TiO2 nanoparticles is an efficient p-type material for fabrication of thin film photo-devices.

In this paper, a CMOS low noise amplifier (LNA) for ultra-wideband (UWB) wireless applications is presented. The proposed CMOS LNA is designed using common-gate (CG) topology at the first stage to achieve ultra wideband input matching. The common-gate has been cascaded with common-source (CS) current-reused configuration to enhance the gain and noise figure (NF) performance of the LNA with low power consumption. In order to ensure maximum power flow from CG input stage to gm boosted CS current-reused stage, parallel-series LC matching has been used. The output-matching network is used to improve the output reflection coefficient. The LNA is designed using standard 90 nm CMOS process for 3.1–10.6 GHz UWB. It exhibits a power-gain (S21) of 19.2–20.8 dB, an NF of 2.3–3.7 dB, a reverse-isolation (S12) of less − 53.8 dB and an S22 of less than − 6 dB for the entire UWB frequency range. The proposed LNA has an input reflection coefficient (S11) of less than − 10.6 dB for 3.1–10.6 GHz. It achieves input 1-dB compression point (P1dB) of − 17 dBm at 6 GHz and input third-order intercept point (IIP3) of − 8 dBm, while it consumes only 5.05 mW of power from a Vdd supply of 0.7 V.

Quantum dots (QDs), which are obtained from semiconductors, own wonderful optoelectronic properties and tunable physical features. Moreover, energy storage is now becoming an imperative concern. These QDs have gained great consideration in recent times. Besides their utilization in sensors, biomolecular analysis, photovoltaic devices, photochemical reagents, fluorescence, and LEDs, these QDs also demonstrate their application in the area of electrochemically storing energy because of anisotropic geometry with size confinement. This chapter deals with complete summary about the recent study and research on QDs for utilization in batteries, including their preparation techniques, structural characteristics and their electrochemical properties.

Numerous important advancements toward developing a novel era of supercapacitors are being published in the past few years. There has been advancement in comprehending theory, synthesizing material, and designing devices concerning supercapacitors. The development of self-charging supercapacitors is rapidly gaining attention due to converting and storing energy in an integrated system. To address the energy shortage, studies have discovered novel techniques for integrating two devices (energy harvester and storage) to create a self-charged device (wearable/versatile electronics) suitable for various applications covering micro to macroscopic level (electric vehicles and fitness monitoring systems). We summarize state-of-the-art progress toward self-charging piezoelectric supercapacitors’ mechanism, materials, and various challenges. In this review, the central theme is a fundamental understanding of energy storage and energy harvesting mechanisms. Secondly, some emerging piezoelectric materials such as polyvinylidene difluoride (PVDF), siloxene, barium titanate (BaTiO3), potassium-sodium niobate (K0.5Na0.5NbO3), oxides, and bio-piezoelectric materials are discussed. The various challenges and future developments regarding further research in this thriving field have also been highlighted.

This paper proposes the Nonlinear Adaptive Filter bank–based artificial bee colony Optimizer (NAFO) based on Wiener filter for inverse modeling of nonlinear fiber link. Here a third-order inverse Volterra-based nonlinear equalizer (VNLE) is used to compensate the fiber nonlinearities using MATLAB Simulink. In the novel method the Mean Square Error (MSE) of the optical link is measured and compared with IIR-filter based technique. The MSE is reported to be 10–14 value lesser in the novel experimental setup consequently the proposed technique shows enhanced and efficient performance.

In this paper, an analytical model is represented to analyze and improve the performance of radio over fiber (RoF) links against nonlinear distortion. RoF transmission link comprised of a phase modulator, polarizer and optical filter is considered. By controlling angles of polarization, the signals are fed to the modulator. Polarizer helps to suppress intermodulation distortion along the considered link. Performance is found in terms of spurious-free dynamic range (SFDR). Results show an improvement of 7.5-dB in SFDR for a polarized link in comparison with the conventional link.

Copper (Cu) doped p-CdS nanoparticles have been synthesized via sol-gel method. The as-synthesized nanoparticles were successfully characterized and implemented for fabrication of Glass/ITO/n-ZnO/p-CdS/Al thin film photodiode. The fabricated device is tested for small (−1 V to +1 V) bias voltage. Results verified that the junction leakage current within the dark is very small. During reverse bias condition, the maximum amount of photocurrent is obtained under illumination of 100 μW/cm2. Electrical characterizations confirmed that the external quantum efficiency (EQE), gain and responsivity of n-ZnO/p-CdS photodiode show improved photo response than conventional p-type materials for such a small bias voltage. It is therefore revealed that the Cu-doped CdS nanoparticles is an efficient p-type material for fabrication of thin film photo-devices.

In this research paper, performance analysis of two different material-based micropillars capacitive antennas is proposed. The method involves formation of self-organized mask, micropillar ...

In this work, an asymmetric piezo-supercapacitor device is fabricated using Nickel/Rochelle Salt (Ni/RS) nanowires array as cathode, Polypyrrole/Nickel/Rochelle (PPy/Ni/RS) nanowires array as anode and rochelle salt based filter paper as a separator and energy harvester. The fabricated device demonstrates self-charging phenomenon due to piezoelectric effect upto 700 mV under a compressive force of 30 N in just 15 s. Moreover, the electrochemical results reveal tremendous cyclic stability with capacitive retention of 99% and 96% for PPy/Ni/RS and Ni/RS nanowires array based electrodes even after 10,000 repeated GCD cycles. In addition, the fabricated Ni/RS//PPy/Ni/RS based asymmetric device shows a high energy density of 166.23 Wh/kg at 0.24 KW/kg. The practical demonstration of the asymmetric supercapacitor is also given by lighting up a green LED. The proposed facile as well as cost-effective approach for smart self-chargeable power package supercapacitor provides new insights for developing next generation all-in-one energy harvesting and storage devices.

Escalating rapidity in the technology leads to the exploration of wearable and mobile devices. There is paramount importance of wearable technology for health management as diseases can be timely monitored which in turn circumvent severe medical situations and decrease economic losses. Wearable technology involves the integration of electronic components into textiles or fabrics for wide range of applications including sensors, medical devices and safety instruments [1, 2]. Textiles, owing to their flexible and capillary characteristic, hold imperative position in the fabrication of rapid and inexpensive point-of-care sensing devices [3]. Metal oxides are affirmed to have potential applications in the fabrication of wearable sensors because of their unique electrical, electrochemical and biocompatible properties. With high surface to volume ratio, the sensitivity, selectivity and catalytic activity of metal oxide semiconductors is greatly enhanced. They serve as excellent candidates for the next generation of wireless sensing and online monitoring applications due to the fast response and long lifetime in different environmental conditions. Among the metal oxide semiconductors, SnO2 is considered as one of the important material due to their number of properties, like biocompatibility, anti-oxidant , anti-bacterial, cytotoxic properties, strong physical and chemical interactions with adsorbed species, high degree of transparency in the visible spectrum, low operating temperature etc. [4]. There is an increased usage of SnO2 as modifier electrode materials because of its astonishing features of thermal stability, biocompatibility, excellent bandgap, cost effective and abundant availability. The surface of working electrode is modified by nanomaterials of SnO2 in combination with various metals, semiconductors and carbon derivatives for improved sensing performance. As per the recent reports, tin oxide in find its applications in the field of glucose sensing [5], gas sensing [6], monitoring heavy metals [7], phenol sensing [8] etc. Apart from the reported applications, tin oxide is proved to be a useful candidate in stealth technology [9]. References Y. Yun, W.G. Hong, N. J.Choi, H.B. Kim, Y. Jun, H.K. Lee, Sci. Rep. 5 (2015) 10904. Skrzetuska, M. Puchalski, I. Krucinska, Sensors 14 (2014) 16816. Li, J. Tian, W. Shen, ACS Appl. Mater. Interfaces 2 (2010) 1. Vidhu, D. Philip, Spectrochim. Acta, Part A 134 (2015) 372. Sedighi, M. Montazer, S. Mazinani, Biosens. Bioelectron. 135 (2019) 192. Wang, C. Zhao, T. Han, Y. Zhang, S. Liu, T. Fei, S. Liu, T. Zhang, Sens. Actuators, B 242 (2017) 269. Wei, C. Gao, F.L. Meng, H.H. Li, L. Wang, J.H. Liu, X.J. Huang, J. Phys. Chem. C 116 (2011)1034. Guo, P. Cai, , J. Sun, W. He, X. Wu, T. Zhang, X. Wang, Carbon 99 (2016) 571. M Jeong, J. Ahn, Y. K. Choi, T. Lim, K. Seo, T. Hong, G. H. Choi, H. Kim, B. W. Lee, S.Y. Park, S. Ju, NPG Asia Materials 12 (2020) 32.

In recent times, Indian IT companies have been facing high attrition rates, especially with young employees having three to seven years of experience. Therefore, this study develops and tests a dynamic model of brand-endorsed employee engagement (EE) and employee retention (ER). Particularly, the carryover and temporal effects of the relationships and constructs are studied to understand how employee behaviour evolves over time. Using two waves of longitudinal data gathered from young employees ([Formula: see text]) of Indian IT companies, the proposed conceptual model is investigated to test the temporal differences in the relationships between internal employer branding (IEB), organisational commitment, EE and ER. Additionally, the impact of employer internal social media usage on the relationships is also examined as an effective human resources (HR) intervention in the evolution process. The findings show that excluding the organisational commitment to EE relationship, the other two relationships between IEB to organisational commitment and EE to ER become stronger over time. Interestingly, while internal social media usage does not exhibit direct effect on organisational commitment or ER, it is instrumental in influencing IEB perception and EE during subsequent periods. Overall, this study offers directions to HR managers in the services sector on how to effectively use social media to engender engagement in employees and ultimately, enhance their intention to stay.

Halide based perovskite materials have fascinated strong attention for being a hopeful candidate for optoelectronic device applications. Single-crystalline halide perovskites exhibit no grain boundaries and possess low trap densities; and are therefore likely to show superior optoelectronic performances in comparison to their polycrystalline film counterparts. In spite of this, their basic perceptive of physico-chemical properties are however controversial to the scientific society. In this review article, we present the deep insight into all the reported protocols available for the synthesis of purely inorganic as well as hybrid halide perovskites (incorporating organic as well as inorganic cation) to achieve high-quality single crystals. On account of advanced characteristics like long carrier recombination lifetime and exciton diffusion length, wide-ranging visible to NIR absorption, high charge mobility, controllable optoelectronic properties etc., hybrid halide perovskites have emerged to be a tough challenger in the optoelectronic research area in comparison to the purely inorganic halide perovskites and have consequently been paid much attention. Therefore, the optoelectronic properties and convenient applications of particularly hybrid halide single-crystal perovskites in various optoelectronic devices like solar cell, laser, high energy ray detector, photodetector, light-emitting diode, etc are highlighted.

In this research work, a 2-inch p-type silicon (Si) wafer with high dielectric constant (11.9) was used as a substrate to minimize substrate conductivity losses, thereby improving the antenna radiation efficiency. A thin gold (Au) film with dimensions of $$350\times 260\times 2\,\upmu \mathrm{m}^{3}$$350×260×2μm3 was deposited on the substrate. Four thin slots having the same dimensions of $$20\times 5\times 2\,\upmu \mathrm{m}^{3}$$20×5×2μm3 were cut from the gold patch to create four different notches, thus forming a horn-shaped multiband microantenna. To evaluate the performance of this useful structure, a horn-shaped patch antenna was designed to achieve operation in multiple frequency bands, namely the C band (6.75 GHz), Ku band (14.734 and 17.76 GHz), and K band (22.45 GHz). To validate the design, various parameters such as the return loss and radiation patterns were obtained experimentally for the fabricated antenna and compared with results from the Ansoft high-frequency structure simulator (HFSS) tool. The simulated and experimental results were found to show good agreement. Ideally, the slots in the horn-shaped patch antenna should be made very thin to achieve a wide impedance bandwidth of 31 %, for $${\vert }{S}_{11}{\vert } \le -10\,\hbox {dB}$$|S11|≤-10dB from 6.75 to 23.15 GHz with high gain and unidirectional radiation pattern for all resonant frequencies.

Functional nanomaterials formed after the combination of a metal oxide and metal play a prominent role in the world of nanotechnology [1]. The interaction between them generates the formation of the interfacial bonds that are mainly responsible for the adhesion strength occurring at the interfaces. Such materials find utilization in numerous fields of electronics, solar cells and chemical sensing [2]. Nanoparticle research presents widespread span for the corroboration of pioneering revelations in the field of medicines, cosmetics, optics and electronics. Astonishing outcomes result from altering the molecular and atomic states of the materials which may not be possible by using them in their original states. Tin dioxide (SnO2) has been colossally used as sensing material in optoelectronic devices, and solid-state gas sensors owing to its stupendous electrical properties escorted by elevated chemical stability [3]. However, very few reports of SnO2 nanoparticles regarding biomolecule detection are available [4]. The sensing characteristics of SnO2 can further be improved by chemical doping with appropriate transition metals such as Pt, Pd, Au, Ag, Ru and Rh [5]. The addition of Au offers suitable platform for the detection of specific analytes [6]. Sol gel method was used to synthesize SnO2 and Au-SnO2 nanoparticles. Structural, morphological and chemical composition of the synthesized nanoparticles was confirmed by XRD, FESEM, TEM, FTIR, and EDS spectroscopic techniques. A frenzy of excitement has generated in electrochemistry by the application of nanotechnology. The electrochemical sensing response of the synthesized nanoparticles was checked after depositing them on ITO substrate. The comparison of the electrochemical performance of Au-SnO2/ITO electrode was done with SnO2/ITO and ITO by cyclic voltammetry (CV), differential pulse voltammetry (DPV) cyclic and electrochemical impedance spectroscopy (EIS). All studies were carried out in phosphate buffer (pH 7.0) at room temperature. The synthesized sensor exhibited good storage stability, specificity and reproducibility with RSD 1.73%. The practical application of the fabricated electrode was demonstrated in real sample with excellent recovery. Reference Wisnios, A. Kiejna, J. Korecki, Towards understanding MgO/Fe interface formation: Adsorption of O and Mg atoms on an Fe(001) surface, Phys. Rev. B 96 (2017) 115418. Nalepka, K. Sztwiertnia, P. Nalepka, Preferred orientation relationships at the Cu/α−Al2O3interface: Identification and theoretical explanation, Acta Mater. 104 (2016) 156–165. Tournier, C. Pijolat, Influence of oxygen concentration in the carrier gas on the response of tin dioxide sensor under hydrogen and methane, Sens Actuators B 61(1999) 43-50. Lavanya, S. Radhakrishnan, C. Sekar, Fabrication of hydrogen peroxide biosensor based on Ni doped SnO2 nanoparticles, Biosen. Bioelectron, 36 (2012) 41-47. Cheraghi, M. A. Taher, H. Karimi-Maleh, R. Moradi, Simultaneous detection of nalbuphine and diclofenac as important analgesic drugs in biological and pharmaceutical samples using a Pt: Co nanostructure-based electrochemical sensor, J Electrochem Soc. 164 (2017) B60-B65. Zhang, X. Liu, S.Wu,M. Xu, X. Guo, S. Wang, Au nanoparticle-decorated porous SnO2 hollow spheres: a new model for a chemical sensor J. Mater. Chem. 20(2010) 6453–9.

Unlike subtractive manufacturing processes, additive manufacturing (AM), also called as 3D printing, can directly produce complex three‐dimensional parts. With near-complete design freedom, it is advantageous in markets that have a demand for customization, flexibility, design complexity, and high transportation costs. This process holds a great deal of potential for manufacturing novel designs and materials for sensors, electronics, energy conversion and storage devices, which were previously inaccessible due to the constraints of traditional manufacturing methods. Like any other manufacturing technology, AM suffers from certain limitations that hinder the use of AM in the field of sensor and energy research: 1) lack of materials available for AM; 2) multi-material AM; and 3) feature size and accuracy. In order to overcome these limitations, my team and I have developed a universal multi-material 3D printer that is capable of printing metals, thermoplastics, gels, pastes, elastomers, and nanocomposites. This newly developed 3D printer is unique in the sense that it employs a screw-based extrusion system. The different materials to be 3D printed (also known as feedstock) are fed into the hopper, the single screw extrusion system mixes and melts the materials, removes any air bubbles, and extrudes the nanocomposite material through a specially developed nozzle ensuring 3D printing without any defects. By using this universal multi-material 3D printer, my team and I have been able to 3D print steel, aluminum, silver, nickel, cobalt, copper, carbon fiber-based nanocomposites, ionic gels, semiconducting materials, titanium dioxide, various thermoplastics, wood, and epoxies. Work is ongoing to increase the resolution of this universal material 3D printer, but more research needs to be carried out to achieve sub 100-micron structures. With the success of this universal material 3D printer, we began to focus on developing 3D printed flexible sensors [1], electronics [2], solid state battries [3] and vanadium redox flow batteries by using recycled vanadium collected from ammonia slag [4]. We are also currently testing the mechanical properties of 3D printed materials against bulk materials in order to understand degradation mechanisms. Considering all of these factors, AM (3D printing) has great potential to become a sustainable manufacturing technology for flexible sensors, electronics and storage devices such as lithium ion batteries, redox flow batteries. This talk will discuss examples of ongoing research work on AM manufactured sensors, systems and devices. Keeping in mind the interdisciplinary in nature of the work, his talk will focuses on the development of sustainable 3D and 4D printable hybrid nanocomposite materials, with applications in energy storage devices, energy harvesting, flexible/stretchable sensors for the Internet of Things (IoT), and soft robotics. Careful consideration is given to synthesis and designing of 3D and 4D printable hybrid materials, so that the processes involved do not compromise the natural environment, or the ability of future generations to maintain sustainable communities. A key insight from our research over the last five years is that 3D and 4D printable hybrid nanocomposite materials for sensors, electronics, energy conversion and storage devices can only be implemented and improved when degradation mechanisms are clearly understood. With the goal of enhanced longevity, our research program aims to contribute to the fundamental understanding of degradation mechanisms, root causes, and failure modes in 3D and 4D hybrid nanocomposite materials. Specific research objectives are to: 1. Develop in-depth knowledge of key degradation mechanisms, from root cause to failure, in 3D and 4D hybrid nanocomposite materials; 2. Develop modeling tools for longevity predictions and demonstrate strategies for longevity enhancements in 3D and 4D hybrid nanocomposite materials; 3. Deploy and test 3D and 4D hybrid nanocomposite materials in real world scenarios. 4. Establish and promote research collaborations between scientists working in sustainable energy engineering, materials science and computer science (machine learning) fields; and 5. Establish collaborations with industrial and academic sectors, and all levels of government, to engage in dialogue on the societal implementation of developed technologies. To realize a sustainable society, it is necessary to promote not only the circulation of resources, but also the efficient use of energy, the development of new technologies associated with the efficient use of energy and materials such as (machine learning and artificial intelligence), recycling of valuable resources, and the production of environmentally friendly materials and systems. My long-term goal is to be part of the solution to help build a sustainable world by training future generations of researchers, ensuring effective knowledge mobilization, and engaging communities to develop sustainable engineering solutions. References: 1. Ajit Khosla, Shreyas Shah, MD Nahin Islam Shiblee, Sajjad Husain Mir, Larry Akio Nagahara, Thomas Thundat, Praveen Kumar Shekar, Masaru Kawakami and Hidemitsu Furukawa (2018). "Carbon fiber doped thermosetting elastomer for flexible sensors: physical properties and microfabrication." Nature Scientific Reports 8, no. 1 (2018):12313 https://doi.org/10.1038/s41598-018-30846-3 2. Sathish K Sukumaran, Takafumi Kobayashi, Shunsuke Takeda, Ajit Khosla, Hidemitsu Furukawa, and Masataka Sugimoto (2019). “Electrical Conductivity and Linear Rheology of Multiwalled Carbon Nanotube/Acrylonitrile Butadiene Styrene Polymer Nanocomposites Prepared by Melt Mixing and Solution Casting.” J. Electrochem. Soc. 2019 volume 166, issue 9, B3091-B3095. https://doi.org/10.1149/2.0171909jes 3. Kumkum Ahmed, Masaru Kawakami, Ajit Khosla and Hidemitsu Furukawa (2019). “Soft Conductive Nanocomposites Based on Ionic Liquid/Carbon Nanotube for 3D Printing of Flexible Electronic Device” Nature- Polymer. Vol 51, pages 511–521 (2019). https://doi.org/10.1038/s41428-018-0166-z 4. He Sun, Hirotaka Takahashi, Yuki Kamada, Kei Sato, Yuta Matsushima, Ajit Khosla, Masaru Kawakami, HidemitsuFurukawa, Philipp Stadler, and Tsukasa Yoshida (2019). “Vanadium Redox Flow Batteries Fabricated by 3D Printing and Employing Recycled Vanadium Collected from Ammonia Slag.” J. Electrochem. Soc. 2019 volume 166, issue 9, B3091-B3095. https://doi.org/10.1149/2.0251909jes

In this proposed work, the design and analysis of a flow sensor to be integrated into a micro-channel is presented. A finite element analysis is carried out to simulate fluid-structure interaction and estimate cantilever deflection under different fluidic flows at constant flow rate. The design of device is based on the determination of geometrical dimensions. A mathematical analysis describing the fluid mechanics and their interaction with the beam is also proposed. The mathematical model is done using finite-element analysis, and a complete formulation for design analysis is determined. Finite element method based Comsol Multiphysics simulations are used to optimize the design in order to determine the fluid velocities after interaction with the free end of the micro-cantilever beam. The device is successfully designed for sensing different fluids.

Many people now use websites as their sole source of news and information, and more and more people use the Web to search for and buy products and services. Loyal users are equally important for all types of websites, but at times the studies have acknowledged that depending on the website characteristics users’ loyalty perception differs i.e. relationships between e-loyalty and its antecedents vary across websites. Despite these acknowledgements, very limited study, if any, has done the comparative analysis of the relative importance of e-loyalty antecedents across different website categories. This study aims to examine the e-loyalty and its antecedent’s relationship across three different categories of websites, namely product website, service website and social networking website. Website categorisation is done on the basis of users’ primary need. The study helps to determine what antecedent should be given closer attention for enhancing loyalty in the respective category. The findings suggest that e-service quality, perceived value, e-trust, e-satisfaction, number of members and number of peers, contributes to generate e-loyalty but with varied significance for different websites. Perceived value, e-service quality and number of peers are the most significant contributor of e-loyalty for product website, service website and social networking website, respectively. Structural equation modelling (SEM) analysis is used for performing empirical analysis using AMOS 20.

Thermal power plant generates a huge amount of fly ash on combustion of coal which is becoming a major environmental issue. Thermal power plants are greatly facing a fly ash management problem. Open dumping of fly ash can deteriorate the groundwater quality by runoff. In the present investigation, the ground water samples were collected from nearby areas of Parichha Thermal Power Plant at six locations during the period of Jan 2014 to May 2014. The samples were taken to the laboratory and analyzed for physico-chemical properties and heavy metal content. The physico-chemical analysis was done for the parameters like pH, Turbidity, Temperature, Electrical Conductivity, Alkalinity, Total Dissolved Solids, Total Hardness, Calcium Hardness and Magnesium Hardness. The concentration of Turbidity, EC and Alkalinity was exceeding the standard at all locations and shows that the groundwater of the area is not fit for drinking. The ground water samples were also analyzed for the presence of lead and cadmium and it was found that lead was exceeding the limit although cadmium was found within the limit.

In assistive technologies involving voice communication, an audio signal with specific shape is needed. In this regard, the design and fabrication of an electrostatic cantilever array is proposed. An array of four metallic micro-cantilevers with dimensions 650 μm × 200 μm × 0.3 μm is fabricated on the silicon substrate. The working principle is based on the electrostatic effect generated due to a conductive path applied between the electrodes. The results are taken from zinc oxide (ZnO) piezoelectric thin film that allows making contact with the vibrating cantilevers on a specified applied input impulse signals. The results demonstrated the switching action of the cantilevers that depends on the polarity of the input pulses. The results obtained are compared with the FEM based (COMSOL Multiphysics) model that is designed and analyzed prior to the experiment. Further, the experimental results showed a good agreement with the predicted values calculated by the simulated model for the input impulse signal applied synchronously to all the micro-cantilevers. However, for asynchronous actuation mode, the result of the as-fabricated device showed a variation than the simulated results. The vibrations are generated periodically from all the cantilevers and the output shows the resultant signals that are very much in the audible frequency range.

This paper presents new gyroscope design architecture with the complete 2-DOF drive and 1-DOF sense mode oscillators that enable the implementation of reduced drive bandwidth without significantly decreasing the sense-to-drive mass ratio of the device. The mechanical structure has an additional anchoring of the decoupling frame mass which allows for the specification of the drive mode resonances and the coupling between the masses independent of the sense mode frequency. This feature eliminates the requirement of an increased design space for realizing a high operational frequency device with robust operation. In addition to this, a reduction in the bandwidth enabled by the additional anchor, leads to the increase in drive mass amplitude, which in turn results in an increased mechanical gain. With this arrangement, the actuation voltage can be further reduced for the same drive displacement as of non-anchored structure. This device has been mathematically modelled considering decoupled frame anchoring effect, designed and then fabricated by using the economical UV-LIGA technology with nickel as a key structural layer of 8 µm thickness; with an overall reduced key structure size of 2.13 by 1.93 mm. Experimental characterization demonstrates the two drive resonances at 8.55 and 10.6 kHz with a bandwidth of 1.0 kHz and the sense mode resonance at 9.2 kHz.

Effect of resistive feedback on performance parameters of Common-Source (CS) low noise amplifier (LNA) is studied in this paper. For this purpose, an ultra low power, low noise figure (NF), high power gain (S 21 ) low noise amplifier (LNA) for narrowband (NB) wireless applications is proposed in this paper. The LNA is designed for 2.4 GHz narrowband (NB) using 90nm CMOS process. It has a 3-dB bandwidth of 2.189–2.637 GHz. It consists of a resistive feedback Common-Source (CS) inductive degeneration main stage followed by Common-Gate (CG) cascoded stage. A series inter-stage inductor between the main stage and the cascoded stage is used to achieve the low NF with desired stability and power gain. The proposed LNA achieves power gain (S 21 ) of 23.4 dB, input return loss (S 1I ) of −2.4 dB, output return loss (S 22 ) of −27 dB and reverse isolation (S 12 ) less than −34.67 dB. The proposed LNA circuit provides acceptable values of input 1-dB compression (P 2 dB) and input third-order intercept point (IIP3) as −32.8 dBm and IIP3 −18.5 dBm respectively. The LNA has NF < 3.21 dB and consumes only 1.44 mW under a power supply of 0.8 V.

This paper presents the new designs of voltage controlled oscillator (VCO) with three transistors XNOR gate as variable capacitive load. Design of three, five and seven stage VCO have been reported using single ended ring topology. CMOS inverter based delay cell is modified with addition of XNOR capacitive load. Output frequency has been controlled by applied voltage to variable capacitive load. Control voltage of VCO has been varied from 1.3 to 2.1 V. Three stage VCO provides output frequency variation in the range of 3.52–3.34 GHz with power consumption variation from 0.81 to 1.76 mW. Five stage VCO shows frequency variation from 2.06 to 1.98 GHz with power consumption varying from 1.35 to 2.94 mW. Moreover, frequency of seven stage VCO varies from 1.47 to 1.41 GHz with varying power from 1.89 to 4.12 mW. Power consumption and output frequency of proposed VCO circuits have been compared with earlier reported circuits and present approach shows considerable improvements.

In this paper, ZnO nano thin film is prepared on n-type Si substrate with orientation using RF sputtering technique and a surface acoustic wave (SAW) based fluorine (F2) gas sensor integrated on ZnO with Palladium (Pd) on top as sensing layer is fabricated and characterized. The input and output interdigital transducer is fabricated of aluminum (Al) using nanolithography technique. The morphological characterization of ZnO thin film is done using scanning electron microscopy and atomic force microscopy. The XRD confirms the formation of ZnO nanostructured thin film. The voltage handling capability of the fabricated device is evaluated with negative and positive bias voltage. The study confirms that the SAW sensor based on ZnO/Si substrate and Pd sensing layer has good characteristic response of F2 gas with different concentration of gas from 0.5 to 20 ppm. The sensor shows good reproducibility and its sensitivity is approximately 2.4 kHz ppm?1.

In this work, zinc selenide (ZnSe) nanowires were fabricated on indium-tin oxide coated glass substrate via template-assisted electrodeposition method from an electrolytic solution of zinc (II) sulphate (ZnSO4·7H2O) and selenium dioxide (SeO2). ZnSe nanowires of diameter 100 nm have been fabricated using polycarbonate track-etch membrane. Electrodeposition was done at 30 °C temperature and the length of the nanowires was controlled by adjusting the deposition time. Both morphological and electrical characteristics were studied. Sample characterization was done using scanning electron microscope and X-ray diffraction. I–V measurements reveal that the ZnSe nanowires have non-linear behavior like Schottky diode characteristics. Further, the ZnSe nanowires were used in astable multivibrator which acts as capacitor to give conventional output behavior. The temperature dependent capacitive properties of ZnSe nanowires reveal that ZnSe nanowire can be used as temperature sensor.

In this paper, a simple non-linear analytical charge control model for the DC and microwave characteristics of AlGaN/GaN MODFET is presented. The effect of parasitic resistances R is also incorporated. The model has also been extended to obtain the expressions for transconductance, drain conductance and cut-off frequency of the device. The model predicts a high transconductance of 502.6mA/mm at 1Vof gate bias and a maximum cut-off frequency of 22.5GHz for a 50nm device gate length, which is important in realizing the device for microwave applications. The extrinsic and intrinsic characteristics show close agreement with the published results proving the validity of the model.

In this paper, an algorithm is developed to attain information from the dark images and an analysis is sought for the impact of brightness adjustment parameter (α) and color hue (λ) on a single dark image. The algorithm appears quite appealing as the quality of the images become clearer. This algorithm is applied on a single dark image for different values of α and λ and out of resultant twenty four images; medium, high and low quality were selected randomly for mean opinion score. A mean score opinion (MOS) is drawn for a set of processed and unprocessed images and the results gathered shows that the processed image gathers valuable information and appeared clear. Results showed that few parts where no information was being noticed before processing the digital image, now provides information to the subject after processing.

A new two-dimensional analytical model for the capacitance-voltage and noise characteristics of a AlGaN/GaN MODFET is developed. The two-dimensional electron gas density is calculated as a function of device dimensions. The model includes the spontaneous and polarization effects. The contribution of various capacitances to the performance of the device is shown. The model further predicts the transconductance, drain conductance, and frequency of operation. A high transconductance of 160 mS/mm and a cut-off frequency of 11.6 GHz are obtained for a device of 50 nm gate length. The effect of gate length on the gate length behaviour of the noise coefficientsP,R, andCis also studied. The effect of parasitic source and gate resistance has also been studied to evaluate the minimum noise figure. The excellent agreement with the previously simulated results confirms the validity of the proposed model to optimize the device performance at high frequencies.

Finite element method (FEM) based simulation has been carried out, and an analytic model of microcantilevers using piezoelectric excitations is proposed. The model is based on the type of the selected material and geometry of the structure. The investigations are carried out with rectangular microcantilevers using silicon as the substrate. The high frequency analytic signals are applied to the input piezoelectric electrodes, and the resultant signal generated at the output piezoelectric electrode is recorded and analyzed. The analysis of the results showed that the proposed system is capable of generating a low frequency signal. Two microcantilevers with different dimensional aspects are used, and the results verified the application of microcantilever array as a low frequency signal generator.

Here, we report a luminescent cathode buffer layer (CBL) for power conversion efficiency (PCE) enhancement of organic solar cells (OSCs). ZnO doped with Aluminum (Al) and Europium (Eu) was cast as CBL by a solution-processed method. CBL serves a dual purpose by acting both as a spectral conversion and an electron transporting layer. The luminescent ZnO:Al,Eu CBL layer has broad absorption spanning the ultraviolet (300–400 nm) spectrum, contributing to absorption enhancement. Moreover, the emission of CBL layer overlaps with the absorption of poly [N -9′-heptadecanyl-2,7-carbazole- alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) polymer thus elevating the overall absorption of the active layer and improving the photocurrent. With this ZnO:Al,Eu CBL in the inverted device configuration (ITO/CBL/active layer/MoOx/Al), an enhanced power conversion efficiency (PCE) of 6.9% was obtained while the device with pristine ZnO as CBL showed PCE of 5.9%. A blend of PCDTBT donor and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) acceptor was used as an active layer in both the cases. In ZnO:Al,Eu CBL layer, Al doping improves the conductivity, while Eu doping significantly enhances the emission in the visible region by down-shifting the incoming solar UV light to the visible range which overlaps with the absorption of PCDTBT polymer resulting in energy transfer and improved overall device efficiency. The findings of the study show the significance of luminescent ZnO:Al,Eu nanoparticle CBL in enhancing the performance of organic solar cells.

Lead halide perovskites have displayed the highest solar power conversion efficiencies of 23% but the toxicity issues of these materials need to be addressed. Lead‐free perovskites have emerged as viable candidates for potential use as light harvesters to ensure clean and green photovoltaic technology. The substitution of lead by Sn, Ge, Bi, Sb, Cu and other potential candidates have reported efficiencies of up to 9%, but there is still a dire need to enhance their efficiencies and stability within the air. A comprehensive review is given on potential substitutes for lead‐free perovskites and their characteristic features like energy bandgaps and optical absorption as well as photovoltaic parameters like open‐circuit voltage (V OC), fill factor, short‐circuit current density (J SC), and the device architecture for their efficient use. Lead‐free perovskites do possess a suitable bandgap but have low efficiency. The use of additives has a significant effect on their efficiency and stability. The incorporation of cations like diethylammonium, phenylethyl ammonium, phenylethyl ammonium iodide, etc., or mixed cations at different compositions at the A‐site is reported with engineered bandgaps having significant efficiency and stability. Recent work on the advancement of lead‐free perovskites is also reviewed.

Inspired from continuous growth in the field of low power and low noise wireless communication devices, a low noise amplifier (LNA) using self-body biased common-gate (CG) configuration is presented in this paper. The proposed LNA is designed for 3–14[Formula: see text]GHz ultra-wideband (UWB) frequency range using 90[Formula: see text]nm CMOS process. Common-gate configuration with self-body biasing has been used at the input stage to provide wideband input matching with low noise figure (NF) for the complete UWB frequency. An impedance matching network consisting of parallel to series RLC network has been used between common-gate and cascaded common source (CS) stages. Two stages of the CS configuration have been used for bandwidth enhancement and to increase the power gain (S[Formula: see text]) with acceptable NF. Buffer stage at the output has been used to achieve output reflection coefficient (S[Formula: see text]) less than [Formula: see text]10.8[Formula: see text]dB. The proposed LNA achieves an average S[Formula: see text] of 15.9[Formula: see text][Formula: see text][Formula: see text]0.7[Formula: see text]dB with a maximum of 16.7[Formula: see text]dB at 3.0[Formula: see text]GHz and NF of 1.68–2.7[Formula: see text]dB for 3.1–10.6[Formula: see text]GHz UWB frequency range. It provides input reflection coefficient (S[Formula: see text]) less than [Formula: see text]10.2[Formula: see text]dB, reverse isolation (S[Formula: see text]) less than [Formula: see text]75.8[Formula: see text]dB and a NF of 1.68–4.0[Formula: see text]dB throughout the proposed UWB frequency range. The proposed LNA provides input 1[Formula: see text]dB compression point (P1dB) of [Formula: see text]13[Formula: see text]dBm and input third-order intercept point (IIP3) of [Formula: see text]8[Formula: see text]dBm at 6[Formula: see text]GHz. It consumes 20.1[Formula: see text]mW of power from a 1.2[Formula: see text]V power supply.

The objective of this work is to implement differential phase shift keying (DPSK) encoded multiple data channels and local oscillator frequency over a common optical fiber with wavelength conversion using semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) and to recover the data signals by using different recovery schemes. The crosstalk penalties are kept at minimum value. One frequency up-converter is used in the system to reduce the complexity and cost of the system. An error free transmission of 1 Gbps differential phase-shift keying (DPSK) data at 2.5 GHz to an optical radio frequency (RF) signal having the frequency of 30 GHz is achieved through the designed system. The conversion efficiency at f RF + f IF is found to be maximum when the optical local oscillator power is approximately −2.5 dBm. Further, the electric power has also been measured for the upconverted and downconverted signal which clearly indicates that crosstalk is not being imposed on the signals by SOA-MZI.

In this paper, an analytical model is developed for power penalty in radio over fiber (RoF) systems. It includes phase noise from laser source, radio frequency (RF) oscillator, chromatic dispersion and its higher order components. It has been observed that there is a significant effect of dispersion, its higher order components, laser phase noise and RF phase noise on power penalty in a RoF single side band (SSB) modulation link. The power penalty has been found in the range of [2.1 and 3.2] dB due to increase in laser line-width from [10 to 620] MHz in the presence of first order, second order (2OD) and third order (3OD) order dispersion respectively. While increase in radio frequency oscillator line-width from [1 to 5] Hz induces power penalty of 40 dB in presence of first order dispersion and 42 dB in presence of 2ODand 3OD at carrier frequency 30 GHz at a transmission distance of 10 km.

In this paper, we present a new analytical model for frequency as well as transient analysis of a 3-DOF gyro-accelerometer system having 2-DOF in drive and 1-DOF in sense direction respectively. The model constructs lumped parameter differential equations by vector analysis associated with each degree of freedom that comprises Coriolis action, Euler's action and action due to external acceleration along with biasing counterparts. These coupled differential equations are then solved explicitly in the frequency domain by taking their Laplace transforms. Based on these formulations, a thorough system analysis has been carried out keeping in view the various parameters and issues related to the device design. Furthermore, a discriminating scheme for time varying angular rate and linear acceleration by combining the structural model of a gyro-accelerometer with the demodulation and filtering processes to investigate frequency response of a micro gyro-accelerometer has also been presented by taking into account the presently derived settled transient solution of sense mode response. Finally we have verified the present model with MATLAB Simulink, showing their excellent agreement with each other.

The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculations and numerical analysis for the microstrip patch antennas. In this paper, two different designs have been modelled and analyzed and both designs are based on the rectangular patches. The feeding point of one design is inside the patch while the other design contains feeding point outside the patch is T shaped. The computational analysis showed some interesting results for radiation pattern and far field domain. For these designs, the characteristic impedance taken is 50 Ω and the operating frequency domain is 1.4 to 1.7 GHz. The microstrip patch antennas are encapsulated in the inert spherical atmosphere of 20 mm thickness containing air inside it.

In present work two new designs for single bit full adders have been presented using three transistors XOR gates. Adder having twelve transistors shows power consumption of 1274µW with maximum output delay of 0.2049ns. Power consumption and maximum output delay shows variation [1274 - 141.77] µW & [0.2049 – 0.4167] ns with varying supply voltage from [3.3 - 1.8] V. Further, reverse body bias technique for power reduction has been applied to adder. Adder with reverse body bias shows power consumption variations of [1270 - 1067.60] µW with varying NMOS reverse bias from [0.0 to - 2.0] V. Delay of adder shows variations [0.2049 - 0.2316] ns with reverse bias variation [0.0 to 2.0] V. Simulations have been carried out at different supply voltage with increasing reverse biased applied to NMOS transistor and results shows improvements in power consumption of adder. A comparison with earlier reported circuits have been presented and proposed circuit’s shows less power dissipation.

In this paper, optical communication system at 10.24 Tb/s using NRZ modulation for 1024 channels with channel spacing of 0.2 nm has been simulated. The performance of the designed dense wavelength division multiplexing (DWDM) system has been executed for evaluation in terms of BER, Q-factor, and eye diagrams. It has been observed that signal received at highest distance without dispersion compensation in good quality is 90 km with an average BER of 10−9 in S, C, L, U-bands and up to 1728.3 nm wavelength; moreover Q-factor is above the threshold value for DWDM system to implement an optical communication link. The system with NRZ modulation format shows good performance up to 90 km in all spectral bands designated for optical fiber communication, but at the distance of 120 km communication link is possible in S, C, and L-bands and at 150 km up to 1565 nm, i.e., C-band only.

Synthesis of copper-telluride nanowires has been carried out using template-assisted electrodeposition technique. The polycarbonate template is supported on a copper substrate. The synthesized nanowires were characterized using scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The SEM image has confirmed the satisfactory deposition of the CuTe nanowires having 100 nm diameters as expected. The investigations for the optical properties of the nanowires were carried out using He-Ne laser. The analysis of the images so obtained by a high resolution digital camera at different orientations with respect to the incident light has shown that CuTe nanowires exhibit a distinct intensity patterns as compared to the patterns obtained with the available copper thin film depositions.