Showing papers by "Motilal Nehru National Institute of Technology Allahabad published in 2019"

A review on overall control of DC microgrids

Abstract: Due to inherent advantages of DC system over AC system such as compatibility with renewable energy sources, storage devices and modern loads, Direct Current Microgrid (DCMG) has been one of the key research areas from last few years. The power and energy management in the DCMG system has been a challenge for the researchers. MG structure and control strategies are the integrated part of the power and energy management system. This paper covers all the aspects of the control of DCMG, whether it is DC bus voltage, power or energy related. Different MG Structures with their comparative analysis has been given in this paper. Various control schemes: Basic control schemes like centralized, decentralized and distributed control and multilevel control scheme such as hierarchal control has been discussed. The Power management in grid-connected, Islanded mode and transition mode has been presented. Different energy management strategies have been presented as energy management plays very important role in optimizing the size and rating of energy storage system and their maximum utilization. The energy management of a battery and super capacitor based HESS in all configurations has also been discussed and finally, future trends in further research are presented.

Nanosilica: Recent Progress in Synthesis, Functionalization, Biocompatibility, and Biomedical Applications

Abstract: Silica nanoparticles (Si-NPs) are widely explored in biomedical applications due to their high surface area, excellent biocompatibility, and tunable pore size. The silica surface can be readily fun...

Green synthesis of nanoparticles: A greener approach for a cleaner future

Abstract: Nanotechnology, the study of matter at the nanoscale (i.e., between 1–100 nm), has opened up novel dimensions in the field of biotechnology and nanomedicine, along with various other important applications such as drug delivery, electronics, cosmetics, and biosensors. Nanoparticles of varied shapes and sizes can be synthesized by using physical, chemical, or biological pathways. However, exploiting physical and chemical routes lead to high energy consumption, low yield, high cost, and environmental damage by employing harsh reducing agents. The biological pathways involve the use of microorganisms (bacteria, fungi, yeast, algae, etc.) or plants, and using microorganisms is riskier because of the pathogenicity issue; it also requires maintenance of large cultures. Therefore, synthesis of nanoparticles with greener methods is preferred. In this chapter, we present a generalized view of green synthesis for the generation of nanoparticles involving plants or their parts as a cost-effective, simpler, and eco-friendly approach. The various factors affecting the green synthesis of nanoparticles are also considered and explained.

Experimental investigation on wire electric discharge machining (WEDM) of Nimonic C-263 superalloy

Abstract: Nimonic C-263 superalloy offers a wide range of outstanding properties, namely, high-temperature resistance, high specific strength, high thermal fatigue, and hot corrosion resistance. The concern ...

A Transient Component Based Approach for Islanding Detection in Distributed Generation

Abstract: In this paper, transient response of the microgrid caused due to unintended switching events and faults have been investigated in distributed generation (DG) system. The proposed technique is based on two new criteria transient index value (TIV) and positive sequence superimposed current angle at point of common coupling. The proposed method utilizes three phase voltage signals at DG end to compute the TIV. The performance of the proposed integrated approach has been evaluated on a sample test system and a practical distribution network consisting of combined heat and power plant, wind turbine generators, and photovoltaic system. The simulation results demonstrate that the proposed technique exhibits high reliability and leads to faster detection of islanding condition as compared to the existing passive islanding detection methods not only for zero active and reactive power mismatch conditions, but also for transient events caused due to nonlinear loads.

Molecular subtypes of colorectal cancer: An emerging therapeutic opportunity for personalized medicine.

Abstract: Molecular subtypes-based therapies offer new potential framework for desired and precise outcome in clinical settings. Current treatment strategies in colorectal cancer are largely 'one drug fit all' model for patients that display same pathological conditions. However, CRC is a very heterogenous set of malignancy that does not support for above criteria. Each subtype displays different pathological and genetic signatures. Based on these features, therapeutic stratification for individual patients may be designed, which may ultimately lead to improved therapeutic outcomes. In this comprehensive review, we have attempted to briefly outline major CRC pathways. A detailed overview of molecular subtypes and their clinical significance has been discussed. Present and future methods, governing CRC subtyping in the era of personalized therapy with a special emphasis on CMS subtypes of CRC has been reviewed. Together, discovery and validation of new CRC patient stratification methods, screening for novel therapeutic targets, and enhanced diagnosis of CRC may improve the treatment outcome.

Creativity, Proactive Personality and Entrepreneurial Intentions: Examining the Mediating Role of Entrepreneurial Self-efficacy:

Abstract: The study aimed to explore the role of creativity and proactive personality on management student’s entrepreneurial intention. The study also proposed entrepreneurial self-efficacy to media...

Nanomaterials and microbes' interactions: a contemporary overview.

Abstract: Use of nanomaterials in the field of science and technology includes different fields in food industry, medicine, agriculture and cosmetics. Nanoparticle-based sensors have wide range of applications in food industry for identification and detection of chemical contaminants, pathogenic bacteria, toxins and fungal toxins from food materials with high specificity and sensitivity. Nanoparticle–microbe interactions play a significant role in disease treatment in the form of antimicrobial agents. The inhibitory mechanism of nanoparticles against different bacteria and fungi includes release of metal ions that interacts with cellular components through various pathways including reactive oxygen species (ROS) generation, pore formation in cell membranes, cell wall damage, DNA damage, and cell cycle arrest and ultimately inhibits the growth of cells. Nanoparticle-based therapies are growing to study the therapeutic treatments of plant diseases and to prevent the growth of phytopathogens leading to the growing utilization of engineered nanomaterials. Hence, with this background, the present review focuses thoroughly on detailed actions and responses of nanomaterials against different bacteria and fungi as well as food sensing and storage.

Facile synthesis of CuO nanowires and Cu2O nanospheres grown on rGO surface and exploiting its photocatalytic, antibacterial and supercapacitive properties

Abstract: The control over the water pollution caused by the organic and biological pollutants is one of the challenging tasks for the scientific community. Here, we have focused to develop materials which can be used to remove both types of water pollutants and also assist in solving problems related to the energy crisis. The CuO, Cu2O, rGO-CuO and rGO-Cu2O of different shapes (sphere, rod and wire) and crystal phases were synthesized and their photocatalytic, antibacterial and supercapacitive properties were investigated. The photocatalytic activity of the synthesized products was measured against methylene blue (MB) dye under the direct sunlight while the antibacterial activity was tested against Klebsiella (gram-negative) and S. aureus (gram-positive) microbes. The electrochemical measurements revealed better supercapacitive performance of the rGO-CuO and rGO-Cu2O nanocomposites.

Quantization based multiple medical information watermarking for secure e-health

Abstract: In this paper, an improved wavelet based medical image watermarking algorithm is proposed. Initially, the proposed technique decomposes the cover medical image into ROI and NROI regions and embedding three different watermarks into the non-region of interest (NROI) part of the transformed DWT cover image for compact and secure medical data transmission in E-health environment. In addition, the method addressing the problem of channel noise distortion may lead to faulty watermark by applying error correcting codes (ECCs) before embedding them into the cover image. Further, the bit error rates (BER) performance of the proposed method is determined for different kind of attacks including ‘Checkmark’ attacks. Experimental results indicate that the Turbo code performs better than BCH (Bose-Chaudhuri-Hochquenghem) error correction code. Furthermore, the experimental results validate the effectiveness of the proposed framework in terms of BER and embedding capacity compared to other state-of-the-art methods. Therefore, the proposed method finds potential application in prevention of patient identity theft in e-health applications.

PLA-coated sisal fibre-reinforced polyester composite: Water absorption, static and dynamic mechanical properties:

Abstract: In the present work, a novel physical treatment (PLA coating) of sisal fibres and its influence on the water absorption, static and dynamic mechanical properties of its composites has been presente...

A review on the taxonomy, factors associated with sound absorption and theoretical modeling of porous sound absorbing materials

Abstract: The sound is the pressure disturbance created over air particles above and below atmospheric pressure. It is a mechanical wave which requires a medium to propagate. The sound can generate from a source, then travels through a medium and finally is received by the receiver. The noise is an unpleasant or unwanted sound that is undesired by the receiver. This unwanted sound is absorbed by the sound absorbing (SA) materials. This paper presents a complete comprehensive literature survey for the SA materials and organized the information in the following manner. First, the phenomenon behind SA mechanism is being explained, then the detailed information of existing SA materials with their classification is reported. After that, the factors associated with the sound absorption that influences the sound absorption coefficient (SAC) is being presented. Finally, the theoretical models for porous materials are being discussed followed by the details of price comparison of natural and synthetic fiber-based sound absorbers and the applications of SA materials of various acoustical products. There are a lot of researches going on to develop new acoustic materials and hence this paper will help the researchers to know about the existing SA materials and also help them to develop new acoustic materials by considering significant information related to sound absorption.

Epigenetic Biomarkers in the Management of Ovarian Cancer: Current Prospectives.

Abstract: Ovarian cancer (OC) causes significant morbidity and mortality as neither detection nor screening of OC is currently feasible at an early stage. Difficulty to promptly diagnose OC in its early stage remains challenging due to non-specific symptoms in the early-stage of the disease, their presentation at an advanced stage and poor survival. Therefore, improved detection methods are urgently needed. In this article, we summarize the potential clinical utility of epigenetic signatures like DNA methylation, histone modifications, and microRNA dysregulation, which play important role in ovarian carcinogenesis and discuss its application in development of diagnostic, prognostic, and predictive biomarkers. Molecular characterization of epigenetic modification (methylation) in circulating cell free tumor DNA in body fluids offers novel, non-invasive approach for identification of potential promising cancer biomarkers, which can be performed at multiple time points and probably better reflects the prevailing molecular profile of cancer. Current status of epigenetic research in diagnosis of early OC and its management are discussed here with main focus on potential diagnostic biomarkers in tissue and body fluids. Rapid and point of care diagnostic applications of DNA methylation in liquid biopsy has been precluded as a result of cumbersome sample preparation with complicated conventional methods of isolation. New technologies which allow rapid identification of methylation signatures directly from blood will facilitate sample-to answer solutions thereby enabling next-generation point of care molecular diagnostics. To date, not a single epigenetic biomarker which could accurately detect ovarian cancer at an early stage in either tissue or body fluid has been reported. Taken together, the methodological drawbacks, heterogeneity associated with ovarian cancer and non-validation of the clinical utility of reported potential biomarkers in larger ovarian cancer populations has impeded the transition of epigenetic biomarkers from lab to clinical settings. Until addressed, clinical implementation as a diagnostic measure is a far way to go.

Biosorption valorization of floating and submerged macrophytes for heavy-metal removal in a multi-component system

Abstract: This study comprises the comparative evaluation of floating (Azolla filiculoides) and submerged (Hydrilla verticillata) macrophytes for potential biosorption of Cu(II), Cr(VI), As(III) and Pb(II) from aqueous solution in a multi-component study. Statistically valid Plackett–Burman design of experiments was employed with four heavy metals at two different levels by varying their initial concentration in the range 10-50 mg L−1 for both the macrophytes. The maximum removal efficiency for Pb(II) was obtained for both the biosorbents, i.e., Azolla sp. (81.4%) and Hydrilla sp. (84.3%) within 4 h of the experimental runs, with an initial concentration of 10 mg L−1 of all the heavy metals. Followed by Pb(II) removal, a declining trend for the removal (%) for Cu(II), As(III) and Cr(VI) was obtained, for all the experimental runs. Also, the minimum removal (%) for all the experimental runs was attained at 25 mg L−1 (maximum) for all the heavy-metal concentration level. The removal efficiency (%) trends follow the order: Pb(II) > Cu(II) > As(III) > Cr(VI) for both the biosorbents. Analysis of variance and Student’s t test of the metal bioremoval revealed that main (individual) effect due to the metals was highly significant (P value < 0.05) on each other’s removal. Student’s t test results revealed that both Pb(II) and Cu(II) strongly inhibited both Cu(II) removal (P value < 0.01), while Cr(VI) has only inhibitory effect on Pb(II) removal. Henceforth, all these results simultaneously depicted good potential of the aquatic macrophytes for the biosorption capability of heavy metal and the effect of individual metals on each other’s removal in the multi-component system.

Analysis of double diffusive convection in electroosmosis regulated peristaltic transport of nanofluids

Abstract: In-depth understanding of flow and pumping characteristics of the nanofluids in a narrow fluidic channel is required for accurate control of micropumps. The present paper studies the nanofluids flow driven by the combined effects of peristaltic pumping and external electric field through microchannel. Double diffusive convection in nanofluids is examined. Buoyancy effects due to change in temperature, solute concentration and nanoparticle volume fraction are also taken into account. Poisson–Boltzmann, momentum, energy, solute concentration, and nanoparticle volume fraction equations are considered to govern the nanofluids flow. Governing equations are simplified under the lubrication theory and Debye-Huckel linearization. Influences of Joule heating, electric double layer thickness, electroosmostic velocity, Grashof numbers, thermophoresis and Brownian motion on flow characteristics, pumping characteristics, and skin friction coefficient are computed using Mathematica software. Trapping phenomenon is also examined under the effects of pertinent parameters. Present analysis reveals that flow characteristics and pumping characteristics improve with negative Joule heating effects. The findings of present analysis can be utilized in clinical implications like drug delivery systems, cell therapeutics, and particles filtrations etc.

Output power smoothing control approaches for wind and photovoltaic generation systems: A review

Abstract: Wind and photovoltaic generation systems possess fluctuating output power due to intermittency in wind speed and solar irradiance which needs to be smoothed before supplying power to the grid for a proper operation. Several power smoothing methods are developed in recent years for wind and photovoltaic systems. This paper presents an extensive review of the output power smoothing methods considering the use of the energy storage system (ESS). In general, the smoothing of fluctuating power is carried out with an ESS such as a battery energy storage system, fuel cell/electrolyzer, superconducting magnetic energy storage, flywheel energy storage system, energy capacitor system as well as without any energy storage system. As the installation and maintenance cost of ESS-based smoothing methods are high, the existing approaches of power smoothing can be broadly categorized into with and without ESS. This paper discusses the merits and demerits of the existing research in power smoothing approaches and proposes key future directions. Moreover, a comparative study of some well-known smoothing techniques is presented for a simple power system with wind, Photovoltaics and batteries.

Highly sensitive refractive index sensor based on D-shaped PCF with gold-graphene layers on the polished surface

Abstract: D-shaped photonic crystal fiber (PCF) sensor in the infrared spectrum is proposed to detect the analytes/liquids of different refractive indices (RIs) ranging from 1.32 to 1.40. To observe the effect of surface plasmon a thin layer of gold was deposited on the D-shaped PCF. Then a flake of graphene was deposited on the layer of gold. Graphene improves the detection capability of PCF sensors because of its excellent molecule adsorption property. Its large surface area and rich π conjugation make it a suitable dielectric layer for sensing. The proposed sensor is designed and numerically analyzed using finite element method. The thickness of the gold, graphene layer and the diameter of the two large air holes of PCF are varied to study its effect on the sensing characteristics of the proposed SPR-based PCF sensor. It is observed that the sensitivity improved to 33,500 nm RIU−1 with effective RI resolution of 2.98 × 10-5 RIU which makes the device more competitive among various plasmonic sensors.

Development of Blown Polylactic acid-MgO Nanocomposite Films for Food Packaging

Abstract: Hitherto the unreported development of blown PLA/MgO nanocomposite (NC) food packaging films, employing an industrial level melt-processing setup is presented. 5 wt% reinforced PLA/MgO NC extrudates are prepared at first, to assess the feasibility of production of large quantity of blown films by the extrusion method. Based on successful outcomes of the preliminary trials, up to 3 wt% PLA/MgO NC films are eventually prepared for testing and characterization of key mechanical, barrier, optical, thermal and anti-bacterial properties. The tensile strength and plasticity are found to improved by nearly 22% and 146% respectively for the 2 wt% MgO reinforced films. The oxygen and water vapour barrier properties improve by nearly 65% and 57% respectively for the 1% formulation. For the 1 wt% NC films around 44% E. coli bacteria are killed after 24 h treatment. Overall, this research establishes the successful production of large scale, sustainable, blown PLA/MgO NC food packaging films.