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Gupta R.,BAHRA University | Singh P.,UIET
Advances in Intelligent Systems and Computing | Year: 2017

Free-space optics (FSO) proved to be a complete replacement of radio frequency (RF) communications in recent years. The performance characteristics of FSO channel is affected by varying climate conditions such as fog, haze, rain, etc. due to their major influence on the laser beam quality propagation through the atmosphere. Attenuation due to fog conditions results in severe effect on the received power. Because of this still FSO has not achieved a mass success in the market. The quality of FSO system is analysed in terms of its signal-to-noise ratio. In this paper, the performance is analysed for different foggy weather conditions like dense, continental, maritime, stable, advection and dense haze using Kim and Kruse models. The density of the fog is governed by liquid water content (LWC) present in the atmosphere. The data rate at an optical wavelength of 1550 nm has also been studied here. © Springer Science+Business Media Singapore 2017.

Sharma A.,BAHRA University | Mishra P.,BAHRA University
1st IEEE International Conference on Power Electronics, Intelligent Control and Energy Systems, ICPEICES 2016 | Year: 2016

In this paper, a hybrid power control scheme is proposed based on sensing metric. Depending upon sensing metric value secondary user switch between underlay and overlay power control scheme. Exploiting the benefits of both schemes, proposed hybrid power control scheme performs significantly better. Simulation results and comparison between schemes are presented to validate theoretical results. © 2016 IEEE.

Kalia S.,University of Bologna | Kalia S.,BAHRA University | Boufi S.,University of Sfax | Celli A.,University of Bologna | Kango S.,Jaypee University of Information Technology
Colloid and Polymer Science | Year: 2014

Interest in nanofibrillated cellulose has been increasing exponentially because of its relatively ease of preparation in high yield, high specific surface area, high strength and stiffness, low weight and biodegradability etc. This bio-based nanomaterial has been used mainly in nanocomposites due to its outstanding reinforcing potential. Solvent casting, melt mixing, in situ polymerization and electrospinning are important techniques for the fabrication of nanofibrillated cellulose-based nanocomposites. Due to hydrophilic character along with inherent tendency to form strong network held through hydrogen-bonding, nanofibrillated cellulose cannot uniformly be dispersed in most non-polar polymer matrices. Therefore, surface modification based on polymer grafting, coupling agents, acetylation and cationic modification was used in order to improve compatibility and homogeneous dispersion within polymer matrices. Nanofibrillated cellulose opens the way towards intense and promising research with expanding area of potential applications, including nanocomposite materials, paper and paperboard additive, biomedical applications and as adsorbent. © 2013 Springer-Verlag Berlin Heidelberg.

Kalia S.,BAHRA University | Sheoran R.,Singhania University
International Journal of Polymer Analysis and Characterization | Year: 2011

It becomes necessary to change the surface morphology of natural fibers to improve the interfacial adhesion between matrix and fibers. To improve the compatibility between natural fibers and hydrophobic polymer matrices, various greener methods have been explored such as plasma treatment and treatments using fungi, enzymes, and bacteria. In the present article, we report the microwave-assisted grafting of methyl methacrylate onto ramie fibers (Boehmeria nivea) and cellulase enzyme-assisted biopolishing of ramie fibers using the bacteria Streptomyces albaduncus. The effects of these treatments on the properties of ramie fibers are discussed. The modified fibers were characterized by using FT-IR, SEM, XRD, and TGA/DTA techniques in order to determine their morphology, crystallinity, and thermal stability. This article also describes the comparative study of properties of biologically and chemically modified ramie fibers. © Taylor & Francis Group, LLC.

Kalia S.,BAHRA University | Kumar A.,Singhania University | Kaith B.S.,Dr. B.R. Ambedkar University
Advanced Materials Letters | Year: 2011

For the synthesis of biocomposite materials for useful applications, it becomes necessary to modify the surface of natural fibers through chemical treatments. Morphology, structure and properties of natural fibers have an obvious effect on the mechanical properties of the biocomposite materials. It is thus necessary to know the morphology, thermal stability and crystalline behavior of original and modified fibers. In present paper, sunn hemp fibers (SHF) were chemically modified with ethyl acrylate and binary monomers (EA+MMA, EA+AA) through microwave radiations induced graft copolymerization. Various reaction parameters were optimized to get maximum grafting (91.8%). Morphology, thermal stability and crystalline behavior of original and modified fibers were investigated. Morphological and thermal studies showed that surface of sunn hemp fibers becomes rough and amorphous through graft copolymerization and thermal stability has been found to be increased. Microwave radiation induced grafting showed a diminutive effect on the crystalline behavior of the sunn hemp fibers as optimum time to get maximum grafting is very less (40 min) in comparison to conventional grafting. Synthesized graft copolymers were used as reinforcing material in preparation of polyhydroxybutyrate biocomposites. It has been observed that graft copolymers improved the interface between fiber and matrix and enhanced the mechanical strength of composites. ©2011 VBRI press.

Kalia S.,University of Bologna | Kalia S.,BAHRA University | Thakur K.,Shoolini University of Biotechnology and Management Sciences | Kumar A.,Shoolini University of Biotechnology and Management Sciences | Celli A.,University of Bologna
Journal of Molecular Catalysis B: Enzymatic | Year: 2014

Use of lignocellulosics has increased enormously in food packaging, composites and textile industries due to their advantages over other traditional materials which include renewability, biodegradability and low cost etc. Lignocellulosic biomass, a major raw material in such industries usually displays a very poor microbial and moisture resistance. Biografting provides innovative solutions to increase the performance of lignocellulosics with new properties including strength and stiffness, resistance to moisture and microbial attack. Biografting of antibacterial and other organic molecules on lignocellulosic biomass is an environmentally friendly and best approach to incorporate desired functionalities for successful industrial applications. Laccase, lipases, peroxidases are among the enzymes being investigated for biografting of organic molecules onto lignin for improved properties of lignocellulosic biomass. Lack of availability of suitable antibacterial molecules in large amounts and cost-effectiveness are the major problems for the commercialization of this method. © 2014 Elsevier B.V.

Any unintended presence of matter or energy in the environment is known as pollution. Noise pollution is one of the pollutions which have its critical effect on the health of existing population. From researches it has been proved that noise may damage human hearing efficiency and neuron cells of brain. Realising that noise pollution is one of the problems of north-east India; I focused to develop some ecofriendly control devices, for the mitigation from noise pollution. To develop a device it needs some data, which is collected from densely populated area of North-East Indian city Gorakhpur which lies between Latitude 26°13'N and 27°29'N and Longitude 83°05'E and 83°56'E. The district occupies the north-eastern comer of the state and has geographical Area 3,321 km2 with Total Population (2011)4,436,275. Due to rapid industrializations and increasing population of the city, it has an exponential growth in number of vehicles and generator sets, which is the basic cause of noise. The population is facing the problem of noise pollution during the travelling hours from 8:00 am till 9:00 pm as studied in survey of the city. In this paper there are some solutions for the noise pollution, through eco-friendly control devices which are designed for the vibration control, which is one of the major causes of generating noise pollution. © 2012 Published by Elsevier Ltd.

Kaith B.S.,National Institute of Technology Jalandhar | Sharma R.,Himachal Pradesh University | Kalia S.,BAHRA University | Bhatti M.S.,Guru Nanak Dev University
RSC Advances | Year: 2014

Guar gum based hydrogel was optimally synthesized using a response surface methodology (RSM) approach for enhanced swelling capacity. Maximization of the water absorption capacity of the synthesized hydrogel was achieved through sequential experimental design based optimization. A fractional factorial screening (Resolution-IV) approach was used to screen significant process variables for maximization of percentage swelling in phase-1. Studied reaction parameters were: (i) monomer concentration, (ii) initiator concentration, (iii) cross linker concentration, (iv) polymerization time, (v) reaction temperature, (vi) vacuum level, and (vii) pH of reaction mixture. A Pareto chart indicated monomer concentration, pH and initiator concentration as significant process variables which were further optimized using full factorial design (23) in phase-2. RSM based center composite design (CCD) was applied to maximize the percentage swelling for the two most significant variables (pH and initiator concentration) in phase-3. Statistical modeling using ANOVA predicted a near neutral range for pH (∼7.0) and an initiator concentration of 21-23 × 10-6mol L-1as optimum operating conditions for maximizing the percentage of swelling (5307%). Hydrogels were found to be highly pH sensitive and should be kept in a narrow range for maximization of percentage swelling. Thus, the sequential experimental design was helpful in achieving two fold increases in percentage swelling in a systematic way. Synthesized super absorbent polymers can be used as effective water-saving materials for horticultural and agricultural applications. This journal is © the Partner Organisations 2014.

Kaith B.S.,National Institute of Technology Jalandhar | Sharma R.,Shoolini University of Biotechnology and Management Sciences | Kalia S.,BAHRA University
International Journal of Biological Macromolecules | Year: 2015

Guar gum-polyacrylic acid-polyaniline based biodegradable electrically conductive interpenetrating network (IPN) structures were prepared through a two-step aqueous polymerization. Hexamine and ammonium persulfate (APS) were used as a cross linker-initiator system to crosslink the poly(AA) chains on Guar gum (Ggum) backbone. Optimum reaction conditions for maximum percentage swelling (7470.23%) were time (min)=60; vacuum (mmHg)=450; pH=7.0; solvent (mL)=27.5; [APS] (molL-1)=0.306×10-1; [AA] (molL-1)=0.291×10-3 and [hexamine] (molL-1)=0.356×10-1. The semi-interpenetrating networks (semi-IPNs) were converted into IPNs through impregnation of polyaniline chains under acidic and neutral conditions. Fourier transform infra-red spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques were used to characterize the semi-IPNs and IPNs. Synthesized semi-IPNs and IPNs were further evaluated for moisture retention in different soils, antibacterial and biodegradation behavior. © 2015 Elsevier B.V.

Kalia S.,BAHRA University | Kumar A.,BAHRA University
Polymer - Plastics Technology and Engineering | Year: 2013

In the present article, we have reported the acrylation, peroxide and permanganate treatments of sunn hemp cellulose fibers using acrylic acid, benzoyl peroxide and potassium permanganate, respectively. Effect of acrylic acid, benzoyl peroxide and potassium permanganate on surface morphology, thermal stability and crystalline behavior was studied. FTIR spectra showed an additional peak at 1733.63 cm-1 due to carboxylic group of acrylic acid, which confirms the acrylation of sunn hemp fibers. Acrylation results in enhanced thermal stability and crystallinity of fibers, whereas, peroxide and permanganate treatments result in decreased thermal stability and crystallinity of sunn hemp fibers. © 2013 Copyright Taylor and Francis Group, LLC.

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