Modification of surface behaviour of Eichhornia crassipes using surface active agent: An adsorption study

Sumanjit,Seema,R.K. Mahajan,Vinod Kumar Gupta 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Eichhornia charcoal modified with cationic surfactant is used as an adsorbent. The characterization wasdone by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, X-ray diffraction, scanningelectron micrograph, and point of zero charge measurements. Effect of contact time, initial dyeconcentration, adsorbent dose and temperature were studied. Experimental data were contemplated forvarious kinetic models and thermodynamic models and interpreted that adsorption followed secondorder kinetic model. Langmuir model deduced the maximum adsorption capacity as 103.2 mg g 1 at323 K. Gibbs free energy, enthalpy and entropy have been calculated and the present adsorption systemis speculated as spontaneous and endothermic in nature.

Synthesis and adsorption properties of mesoporous material for the removal of dye safranin: Kinetics, equilibrium, and thermodynamics

Sumanjit Kaur,Seema Rani,R.K. Mahajan,M. Asif,Vinod Kumar Gupta 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.22 No.-

A highly ordered large pore mesoporous adsorbent MCM-41 is synthesized and characterized by XRD,BET, FTIR and SEM. Effect of contact time, initial dye concentration, adsorbent dose, pH and temperaturewere studied for adsorption of dye safranin on MCM-41. Experimental data were investigated for variousthermodynamic models and kinetic models and corroborated that adsorption followed second orderkinetic model. Langmuir model evidenced the maximum adsorption capacity as 68.8 mg g 1 at 303 K. Thermodynamic parameters surmised that adsorption of safranin on MCM-41 is spontaneous,exothermic and feasible.

ON A GENERALIZED DOUBLE INTEGRAL TRANSFORM

Mahajan, R.R.,Saxena, Rajendra K. Department of Mathematics 1977 Kyungpook mathematical journal Vol.17 No.2

Selective detection of Co²⁺ by fluorescent nano probe: Diagnostic approach for analysis of environmental samples and biological activities

Mahajan, Prasad G.,Dige, Nilam C.,Desai, Netaji K.,Patil, Shivajirao R.,Kondalkar, Vijay V.,Hong, Seong-Karp,Lee, Ki Hwan Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.198 No.-

<P><B>Abstract</B></P> <P>Nowadays scientist over the world are engaging to put forth improved methods to detect metal ion in an aqueous medium based on fluorescence studies. A simple, selective and sensitive method was proposed for detection of Co<SUP>2+</SUP> ion using fluorescent organic nanoparticles. We synthesized a fluorescent small molecule viz. 4,4′-{benzene-1,4-diylbis-[(Z)methylylidenenitrilo]}dibenzoic acid (BMBA) to explore its suitability as sensor for Co<SUP>2+</SUP> ion and biocompatibility in form of nanoparticles. Fluorescence nanoparticles (BMBANPs) prepared by simple reprecipitation method. Aggregation induced enhanced emission of BMBANPs exhibits the narrower particle size of 68nm and sphere shape morphology. The selective fluorescence quenching was observed by addition of Co<SUP>2+</SUP> and does not affected by presence of other coexisting ion solutions. The photo-physical properties, viz. UV-absorption, fluorescence emission, and lifetime measurements are in support of ligand-metal interaction followed by static fluorescence quenching phenomenon in emission of BMBANPs. Finally, we develop a simple analytical method for selective and sensitive determination of Co<SUP>2+</SUP> ion in environmental samples. The cell culture <I>E</I>. <I>coli</I>, <I>Bacillus</I> sps., and <I>M</I>. <I>tuberculosis H</I> <SUB> <I>37</I> </SUB> <I>RV</I> strain in the vicinity of BMBANPs indicates virtuous anti-bacterial and anti-tuberculosis activity which is of additional novel application shown by prepared nanoparticles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> New fluorescent Nano probe developed for detection of Co<SUP>2+</SUP> in aqueous medium </LI> <LI> Selective fluorescence quenching induced by Co<SUP>2+</SUP> only </LI> <LI> Quenching mechanism disclose ground state complexation and ligand (COO<SUP>–</SUP>) – metal (Co<SUP>2+</SUP>) interaction </LI> <LI> Lower detection limit for Co<SUP>2+</SUP> = 0.102 µg/mL </LI> <LI> The practical application includes analysis of environmental samples and biological activities </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparation and Characterization of Oxadiazole Based Electron Transporting Thin Films

Aman Mahajan,Ramanpreet Kaur Aulakh,R. K. Bedi 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.4

To study the effect of aggregation of the 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) molecule in solid state, thin films of PBD have been prepared by the thermal evaporation technique onto glass and quartz substrates under different experimental conditions. These films have been studied for their structural, optical and electrical properties. AFM investigations of the films revealed that the films were smooth, dense and crack free with RMS roughness of 11-14 nm. XRD measurements indicate that films deposited on quartz are more crystalline than films deposited on glass substrate. Both absorption and reflectance spectra over the wavelength range 200 -800 nm have been recorded to find optical parameters, namely, absorption, extinction coefficient, refractive index and dielectric constants. The inter-band transition energies are found to lie within the range 3.45-3.49 eV. Optical studies of the films indicate that PBD molecules preferred J-aggregation. A prominent single emission peak in the range of 370-390 nm has been observed which confirms that the fluorescent property of this molecule is not quenched in the thin film state. The electrical conductivity results for the evaporated films exhibited semiconductor behaviour within the investigated field and temperature range. The nature of the substrate is found to be a useful tool to modify the film morphology and for enhancing the charge transport within the films.

Development of Carbon Nanotubes and Polymer Composites Therefrom

P.K. Jain,Y.R. Mahajan,G. Sundararajan,A.V. Okotrub,N.F. Yudanov,A.I. Romanenko 한국탄소학회 2002 Carbon Letters Vol.3 No.3

Multiwall carbon nanotubes (MWNT) were produced using the arc-discharge graphite evaporation technique. Composite films were developed using MWNT dispersed in polystirol polymer. In the present work, various properties of the polymeric thin film containing carbon nanotubes were investigated by optical absorption, electrical resistivity and the same have been discussed.

Effect of Feed Protein Source on Digestion and Wool Production in Angora Rabbit

Bhatt, R.S.,Sawal, R.K.,Mahajan, A. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.7

Adult German cross $(German{\times}British{\times}Russian)$ angora rabbits (one year age), 32 in number were divided randomly into four groups $(T_1-T_4)$ with equal sex ratio and fed diets containing $T_1$ groundnut cake (GNC); $T_3$, soyaflakes (SF); $T_4$, sunflower cake (SFC) and $T_2$, a mixture of all the three cakes along with green forage as roughage for a period of 9 months. Nine per cent protein was added from each protein source. Fibre level was maintained by adjusting the level of rice phak in the diets. The diets were iso-nitrogenous and contained similar level of fibre. DMI through roughage was not affected due to source of protein in the diet, however, DMI through concentrate was higher $(p{\leq}0.05)$ with SFC diet, which resulted in higher total feed intake in the group $(T_4)$. Body weights increased up to second shearing, thereafter it decreased due to summer depression. Diet containing soyaflakes sustained higher wool yield whereas, it was lowest $(p{\leq}0.05)$ on SFC diet. Wool attributes (staple length, medullation, fibre diameter) were not affected due to source of protein in the diet. Digestibility of fibre and its fractions (ADF, cellulose, hemicellulose) decreased $(p{\leq}0.05)$ with incorporation of SFC in the diets. Balance of calcium was lowest whereas, that of nitrogen was highest with SFC diet $(T_4)$. Biological value of N and net protein utilization was better when different protein sources were mixed together $(T_2)$. Protein quality of soyaflakes proved better for wool production followed by groundnut cake and mixture of three protein sources. Sunflower cake alone or in combination decreased wool production which may be checked by supplementation of amino acids and energy.

Development of Carbon Nanotubes and Polymer Composites Therefrom

Jain, P.K.,Mahajan, Y.R.,Sundararajan, G.,Okotrub, A.V.,Yudanov, N.F.,Romanenko, A.I. Korean Carbon Society 2002 Carbon Letters Vol.3 No.3

Multiwall carbon nanotubes (MWNT) were produced using the arc-discharge graphite evaporation technique. Composite films were developed using MWNT dispersed in polystirol polymer. In the present work, various properties of the polymeric thin film containing carbon nanotubes were investigated by optical absorption, electrical resistivity and the same have been discussed.

Surfactant Assisted Growth of Nanostructured Tin oxide films for gas sensing applications

Kamalpreet Khun Khun,Aman Mahajan,R.K Bedi 대한금속·재료학회 2011 ELECTRONIC MATERIALS LETTERS Vol.7 No.4

Porous nanostructured SnO2 films have been prepared using an ultrasonic spray pyrolysis technique in conjunction with cationic, anionic and non ionic surfactants namely CTAB (Cetyl trimethyl ammonium bromide),SDS (sodium dodecyl sulphate) and PEG (polyethylene glycol) respectively. The effect of surfactants on the structural, electrical, optical and gas sensing properties of SnO2 films were investigated by using different techniques such as X-ray diffraction (XRD), Field emission scanning electroscope microscopy (FESEM), two probe technique and Photoluminiscence (PL) studies. The results reveal that the addition of surfactants in the precursor solutions leads to reduction in crystallite size with significant changes in porosity of SnO2 films. PL studies of the films show emissions in the visible region which exhibit changes in the intensities upon variation of surfactants in the precursor solutions. The prepared films were tested for their sensing behaviour towards chlorine and the results reveal that the films prepared in conjunction with cationic surfactant CTAB exhibits a sensing response of 53.5% towards 20 ppm chlorine at a low operating temperature of 150°C.

SENSOR ELIMINATION IN SWITCHED RELUCTANCE MOTOR DRIVES: AN OVERVIEW AND STATE OF THE ART

M.Ehsani,I.Husain,K.R.Ramani,S.Mahajan 전력전자학회 1992 ICPE(ISPE)논문집 Vol.1992 No.4

Advantages of the switched reluctance motor (SRM) drives make it an attractive candidate for replacing many adjustable speed ac and dc drives in both industrial and consumer applica­tions. The simple, low cost and robust SRM drive can be efficiently operated in hostile envi­ronments, such as under the hood of an automo­bile. The purpose of this paper is to introduce the basic SRM drive concept and present some of the recent shaft sensor and current sensor elimi­nation concepts and new converters which have<br/> been developed to further simplify this motor drive.