Ashutosh Tiwari
Abstract
VBRI Press is pleased to announce ‘European Advanced Materials Congress, (EAMC) during 23 – 25 August 2016, Sweden. It is a three-day international event organised with collaboration of International Association of Advanced Materials (IAAM), and Linkoping University on the Baltic Sea ...
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VBRI Press is pleased to announce ‘European Advanced Materials Congress, (EAMC) during 23 – 25 August 2016, Sweden. It is a three-day international event organised with collaboration of International Association of Advanced Materials (IAAM), and Linkoping University on the Baltic Sea from Stockholm-Helsinki-Stockholm by the Viking Line Cruise M/S Mariella. The goal of congress is to provide a global platform for researchers and engineers coming from academia and industry to present their research results and activities in the field of fundamental and interdisciplinary research of materials science and technology.
Bablu Mukherjee; Asim Guchhait; Yinthai Chan; Ergun Simsek
Abstract
We have studied the optical absorptance of lead sulfide (PbS) quantum dot (QD) coated thin crystalline layered material (TCLM) experimentally and numerically. Starting with the synthesis, fabrication and characterizations, a sample of PbS QDs deposited on trilayer molybdenum disulphide (MoS2) thin film ...
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We have studied the optical absorptance of lead sulfide (PbS) quantum dot (QD) coated thin crystalline layered material (TCLM) experimentally and numerically. Starting with the synthesis, fabrication and characterizations, a sample of PbS QDs deposited on trilayer molybdenum disulphide (MoS2) thin film has been probed locally using a reflection spectrometer set-up. Since transmittance is needed to calculate the absorbtance of the QD film/TCLM sample, we run a set of simulations using a 3D finite-difference time-domain full-wave electromagnetic solver. Based on the agreement between experimental and numerical results for the reflectance spectra, which verifies the accuracy of our QD and TCLM modelling, we have calculated the absorptance. Unlike metal nanoparticle decorated TCLMs in which metal nanoparticles act like induced dipoles and enhance the absorptance, here we have not observed the similar effect; rather we have found that the absorptance of QD film/TCLM sample is almost equal to the summation of QDs’ and TCLM’s individual absorptance in the wavelength range of 450-800 nm.
Amit Kumar Singh Chauhan; Shibin Krishna T.C.; Neha Aggarwal; Monu Mishra; Asad Niazi; Lekha Nair; Govind Gupta
Abstract
Triangular nano-scale pits (TNPs) of Si3N4 are fabricated by reactive nitrogen ion sputtering using low energy nitrogen ions on the Si (553) surface at 500 °C. The electronic structure of the developing Si3N4 interface was monitored in-situ by Auger Electron Spectroscopy (AES) while the ion beam ...
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Triangular nano-scale pits (TNPs) of Si3N4 are fabricated by reactive nitrogen ion sputtering using low energy nitrogen ions on the Si (553) surface at 500 °C. The electronic structure of the developing Si3N4 interface was monitored in-situ by Auger Electron Spectroscopy (AES) while the ion beam induced surface reaction was analysed via X-Ray and Ultraviolet photoemission spectroscopy (XPS & UPS), Photoluminescence and Raman spectroscopy. The morphological development of nanoscale pit structures was observed by Scanning Electron Microscopy (SEM). The formation of Si3N4 was identified by AES, with the appearance of the characteristic reacted Si(LVV) peak at 83 eV, while photoemission spectroscopy confirmed the stoichiometry of Si3N4. The valence band maximum was observed to be located at 2.4 eV below the Fermi level. SEM images showed uniformly distributed Si3N4 TNPs with size varying between 250 to 600 nm (length) and 200 to 400 nm (width). Our work underlines the influence of ion energy and substrate temperature and establishes the conditions for the growth of Si3N3 TNPs by ion induced reactive sputtering.
Nilaya K. Mohanty; Ajay K. Behera; Santosh K. Satpathy; Banarji Behera; Pratibindhya Nayak
Abstract
The Gd-modified BiFeO3-PbTiO3 composites i.e. 0.5BiGdxFe1-xO3-0.5PbTiO3 (BGxF1-x-PT) with x=0.00, 0.05, 0.10, 0.15, 0.20, were prepared by mixed oxide method at high temperature. The structural study reveals that the composites showed tetragonal crystal structure at room temperature and tetragonality ...
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The Gd-modified BiFeO3-PbTiO3 composites i.e. 0.5BiGdxFe1-xO3-0.5PbTiO3 (BGxF1-x-PT) with x=0.00, 0.05, 0.10, 0.15, 0.20, were prepared by mixed oxide method at high temperature. The structural study reveals that the composites showed tetragonal crystal structure at room temperature and tetragonality (c/a ratio) of composites decrease with increase in Gd concentration. The average crystallite size of the composites was found to be in the range of 30-89 nm. Surface morphology of the composites was studied by scanning electron microscopy (SEM). The Goldschmidt tolerance factors of the composites were found to be in the range of 0.989-0.976. The nature of Nyquist plot confirmed the presence of both bulk and grain boundary effects, and non-Debye type of relaxation process occur in the composites. The activation energy of the composites was found to be in the range 0.13-1.38eV. The analyses of ac conductivity data obey the universal agreement with Jonscher’s power law. Further, the explanation of conduction mechanism through correlated barrier hopping (CBH) model was discussed.
Bishnu K. Pandey; Ashutosh K. Shahi; Nitisha Srivastava; Girjesh Kumar; Ram Gopal
Abstract
In the present study we have successfully synthesized cobalt and cobalt oxide NPs in ethanol and double distilled water respectively. Structural and optical characterizations have been performed by X-ray diffraction and UV-Visible absorption spectroscopy respectively. Magnetic characterization has been ...
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In the present study we have successfully synthesized cobalt and cobalt oxide NPs in ethanol and double distilled water respectively. Structural and optical characterizations have been performed by X-ray diffraction and UV-Visible absorption spectroscopy respectively. Magnetic characterization has been performed by vibrating sample magnetometer (VSM). Particle shape and size have been estimated by transmission electron microscopy (TEM). We have studied the effect of cobalt and cobalt oxide NPs on mitotic division of meristamatic roots of Sesbania cannabina. It has been found that cobalt oxide nanoparticles were more toxic than cobalt nanoparticles and both induced various types of chromosomal aberrations in meristamatic root tip cells of sesbania cannabina.
Omar Abbes; Amer Melhem; Chantal Boulmer-Leborgne; Nadjib Semmar
Abstract
This communication describes the development of optimized metallic contacts on Si for thermoelectric applications. Thin solid films of Ni and Pt with the same thickness, were deposited on Si substrates. Two silicides were formed in a vacuum chamber and were studied. The EDX spectroscopy and electron ...
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This communication describes the development of optimized metallic contacts on Si for thermoelectric applications. Thin solid films of Ni and Pt with the same thickness, were deposited on Si substrates. Two silicides were formed in a vacuum chamber and were studied. The EDX spectroscopy and electron microscopy have supported the presence of silicides in the surface of the samples. The thermoelectric study demonstrated that silicides could play a vital role in the enhancement of the electricity generated by thermoelectric materials that are made of Si. Pt silicide was found to be better candidate than three other metallic contacts (Pt, Ni and Ni silicide), but a comparison with other silicides is needed in the future, to get the best electronic contact on thermoelectric materials.
V.K. Sachdev; S.K. Sharma; S. Bhattacharya; K. Patel; N.C. Mehra; V. Gupta; R.P. Tandon
Abstract
Growing electromagnetic pollution caused by the rapid proliferation of sophisticated electronic devices has increasingly invited concerns. Cement based composites are commercially established in constructions, also capable of electromagnetic interference shielding besides other multifunctional utilities. ...
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Growing electromagnetic pollution caused by the rapid proliferation of sophisticated electronic devices has increasingly invited concerns. Cement based composites are commercially established in constructions, also capable of electromagnetic interference shielding besides other multifunctional utilities. Cement matrix a key ingredient in mixes is considered to be the best adhesive that holds together the aggregates. In this work these composites filled with conductive graphite particles were prepared using dry tumble mixing modus operandi followed by compression and subsequent curing with water. Prolong tumble mixing ensures even dispersion of constituents while compression develops a stronger bond to the aggregates besides patterning of graphite particles in cement matrix. This patterning of conductive graphite particles is vital for producing enhanced electrical and dielectric properties. Effects of increasing graphite concentration on electrical properties and electromagnetic interference shielding effectiveness in X band were investigated. The cement with 20 wt% graphite shows an enormous electrical conductivity 2.74 × 10 -1
R. Sriramprabha; M. Divagar; D. Mangalaraj; N. Ponpandian; C. Viswanathan
Abstract
Pristine SnO2 and SnO2/Graphene (SnO2/GN) nanocomposites were prepared via facile hydrothermal method with amended electro catalytic activity towards Dopamine (DA) sensing. X-Ray Diffraction (XRD) pattern revealed the formation of tetragonal crystal system of SnO2 that was retained in both pure metal ...
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Pristine SnO2 and SnO2/Graphene (SnO2/GN) nanocomposites were prepared via facile hydrothermal method with amended electro catalytic activity towards Dopamine (DA) sensing. X-Ray Diffraction (XRD) pattern revealed the formation of tetragonal crystal system of SnO2 that was retained in both pure metal oxide and composite. Fourier Transform – Infrared (FT-IR) transmission spectra evidenced the stretching and bending vibration modes of pure SnO2 and SnO2/GN nanocomposites. The in-plane bending modes of SnO2 and graphatic peaks in graphene oxide (GO) and composite were identified in Raman spectral analysis. Morphology of synthesized materials and uniform distribution of SnO2 on graphene sheet in SnO2/GN composite were observed in Field Emission-Scanning Electron Microscope (FE-SEM). Electrochemical performance of SnO2 and SnO2/GN nanocomposite on modified Glassy Carbon (GC) electrode was evaluated for direct DA sensing using Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Chrono Amperometric techniques. The SnO2/GN nanocomposite showed enhanced charge carrier mobility towards DA in presence of interferences like Ascorbic acid (AA) and Uric acid (UA) compared to pristine SnO2. The limit of detection was calculated as (0.7μM) for (SnO2/GN) which is better than bare SnO2 (6.675 μM). These synergetic behaviors depicting SnO2/GN composite can serve as a promising electrode in sensor transducers in near future.
Mahuya Bandyopadhyay; Hermann Gies; Wolfgang Gr
Abstract
The interpenetrating 3-dimensional channel system of silica MCM-48 has been selected for the deposition of ZnO nanoparticles. The post-synthetic organometallic route was employed to load the mesoporous silica with ZnO-precursor molecule. Calcination of the composite transformed the organometallic sorbate ...
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The interpenetrating 3-dimensional channel system of silica MCM-48 has been selected for the deposition of ZnO nanoparticles. The post-synthetic organometallic route was employed to load the mesoporous silica with ZnO-precursor molecule. Calcination of the composite transformed the organometallic sorbate to the corresponding metal oxide. X-ray powder diffraction, N2-Adsorption and TEM measurement have supported the efficient loading and growth of ZnO particles in the channels of mesoporous silica matrix. EXAFS analysis (ZnK-edges) also complemented the metal uptake. Presence of nano-dispersed and nanosized ZnO particles confined by the mesoporous pore system was established by TEM and EXAFS analysis.
K. Prem Ananth; Sujin P. Jose; A. Joseph Nathanael; Tae Hwan Oh; D. Mangalaraj; A. M. Ballamurugan
Abstract
In this paper, we have reported a successful synthesis of ionic substituted (Si, Sr and Zn) hydroxyapatite (HAp) using chemical precipitation method and the coating of the synthesized materials on surgical grade 316 L SS using electrophoretic deposition technique. The structural, compositional, functional ...
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In this paper, we have reported a successful synthesis of ionic substituted (Si, Sr and Zn) hydroxyapatite (HAp) using chemical precipitation method and the coating of the synthesized materials on surgical grade 316 L SS using electrophoretic deposition technique. The structural, compositional, functional group and morphological characterization of the developed coatings were carried out using XRD, EDX, FT-IR, and FE-SEM. Electrochemical studies such as potentiodynamic polarization, electrochemical impedance studies were performed to evaluate the corrosion resistance imparted by the coatings and was found that considerable resistance was exhibited by the coated samples. Furthermore the coated samples were tested for in-vitro biomineralization ability in simulate body fluid (SBF) solution at different immersion time periods and was found that the thickness of the apatite film was increased with the increase in the immersion time and the surface became entirely covered with apatite. Thus it is opined that the developed Si, Sr, and Zn substituted Hydroxyapatite (I-HAp) coating on 316 L SS substrate would be ideal candidates for bio implant applications.
Ratiram Gomaji Chaudhary; Jay A. Tanna; Nilesh V. Gandhare; Alok R. Rai; Harjeet D. Juneja
Abstract
Nickel nanoparticles (Ni NPs) with a crystalline size of around 30 nm have been synthesized successfully via the chemical reduction method. Ni NPs were obtained through a nickel salt with hydrazine hydrate at 80 °C temperature by using ethylenediamine as protective agent. The synthesized nanoparticles ...
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Nickel nanoparticles (Ni NPs) with a crystalline size of around 30 nm have been synthesized successfully via the chemical reduction method. Ni NPs were obtained through a nickel salt with hydrazine hydrate at 80 °C temperature by using ethylenediamine as protective agent. The synthesized nanoparticles were characterized by using FTIR spectroscopy, powder X-ray diffraction pattern, ultraviolet-visible spectroscopy, energy dispersive X-ray spectroscopy (EDS), thermogravimetry (TG/DTG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The size and morphology behavior of NPs were studied by PXRD, SEM and TEM techniques. Furthermore, its applications studies were carried out as catalyst for Knoevenagel condensation reaction of aromatic aldehydes and malononitrile under solvent free conditions. The efficacy of NPs catalyst was exhibited an excellent recyclability and reusability up to four times without any additional treatment. The silent feature of nickel nanoparticles were found as efficient, cleaner reactions profiles and simple workup. Moreover, its comparative antibacterial activities were performed by using common solvents and sonication under standard method. The antibacterial activities were tested against human bacterial pathogen such as Staphylococcus aureus, Escherichia coli, Klebsiella sp, Enterococcus faecalis and Pseudomonas aeruginosa using well diffusion method. Nonetheless, the antibacterial activities of Ni nanoparticles (20 to 60 ug) were compared with four well known antibiotics i.e. Amikacin (30 mcg), Ciprofloxacin (5 mcg), Gentamicin (5 mcg) and Norfloxacin (10 mcg). The highest antimicrobial activity of Nickel nanoparticles were found against Pseudomonas aeruginosa, Staphylococcus aureus (21 mm) and Klebsiella sp. (20 mm). However, the results reveal an efficient antimicrobial activity against pathogenic bacteria under sonication than common solvent technique.
Abdelhalim Elbasset; Salaheddine Sayouri
Abstract
Structural, piezoelectric and pyroelectric characteristics of sol gel processed BaTiO3 ceramics calcined at different temperatures (500, 600, 700, 800, 900 and 1000°C) and sintered at 1100°C for 8 hours were investigated. The effect of heat treatment (calcinations) on the piezoelectric coefficient ...
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Structural, piezoelectric and pyroelectric characteristics of sol gel processed BaTiO3 ceramics calcined at different temperatures (500, 600, 700, 800, 900 and 1000°C) and sintered at 1100°C for 8 hours were investigated. The effect of heat treatment (calcinations) on the piezoelectric coefficient (d33) and the voltage constant (g33) was shown to be similar to that on the mechanical quality factor (Qm). The values of d33, g33 and Qm increase with increasing temperature and reach their maximum at 1000°C (d33=79.16, g33=28.01 and Qm=199). The results revealed that the full width at half maximum (FWHM) of the bands B1and E(TO3+ LO2) has high value and is essential for obtaining BT ceramics having good properties.
Swarup Roy; Sudipta ponra; Tapas Ghosh; Ratan Sadhukhan; K. C. Majumdar; Tapan Kumar Das
Abstract
The interaction between pyrano [3, 2-f] quinoline derivatives (TPQ) and bovine serum albumin (BSA) was studied using spectroscopic techniques. The TPQ quench the fluorescence of BSA through dynamic quenching. According to Van’t Hoff equation, the thermodynamic parameters were calculated and which ...
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The interaction between pyrano [3, 2-f] quinoline derivatives (TPQ) and bovine serum albumin (BSA) was studied using spectroscopic techniques. The TPQ quench the fluorescence of BSA through dynamic quenching. According to Van’t Hoff equation, the thermodynamic parameters were calculated and which indicated hydrogen bonds and van der waals forces played a prime role in stabilizing the BSA–TPQ complexes. Also, the average binding distance (r) and the critical energy transfer distance (Ro) between TPQ and BSA were also evaluated according to Förster’s non-radiative energy transfer (FRET) theory. What is more, UV-visible and circular dichroism results showed that the addition of TPQ changed the secondary structure of BSA and led to a reduction in content α-helix (%) content. It was also observed that TPQ shows cell staining property to the cultured HeLa cell line. Theoretical docking study of interaction between BSA and TPQ also supported the experimental results. All the results suggested that BSA experienced substantial conformational changes induced by TPQ; this may be useful to study synthetic organic molecules for their application as pharmaceuticals.
Jagriti Narang; Nidhi Chauhan; Ashish Mathur; Vivek Chaturvedi; C.S. Pundir
Abstract
In present work, we employed gold nanorods for electrochemical sensing of bilirubin. A new method is developed by using covalently immobilized bilirubin oxidase (BOx) on gold nanorods and employed gold microelectrode. The sensing interface materials were characterized by dynamic light scattering (DLS), ...
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In present work, we employed gold nanorods for electrochemical sensing of bilirubin. A new method is developed by using covalently immobilized bilirubin oxidase (BOx) on gold nanorods and employed gold microelectrode. The sensing interface materials were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The optimum response was observed at pH 7 and 35 ºC. The linear working range of the biosensor is 0.01 -500 µM. Fabricated sensing technology showed good evaluation parameters like precision (2.2 % and 3.2 %) and analytical recovery (98.2 % and 97.4 %). Bilirubin biosensor can be employed for early detection of bilirubin in blood serum to check jaundice,hyperbilirubinia and physiologic jaundice in infants.
Swarup Roy; Sintu Ganai; Raj Kumar Nandi; K.C. Majundar; Tapan K. Das
Abstract
The interaction between pyrimidine-annulated spiro-dihydrofuran (PSDF) with bovine serum albumin (BSA) was investigated following spectroscopic studies. The results indicate that dynamic quenching contributes to the fluorescence quenching of BSA by PSDF. The binding constant (K) and the number of binding ...
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The interaction between pyrimidine-annulated spiro-dihydrofuran (PSDF) with bovine serum albumin (BSA) was investigated following spectroscopic studies. The results indicate that dynamic quenching contributes to the fluorescence quenching of BSA by PSDF. The binding constant (K) and the number of binding sites (n) were calculated from the recorded spectra. Based on the Förster’s non-radiative energy transfer theory, the average binding distance between BSA and PSDF was estimated. The synchronous fluorescence spectra and circular dichroism indicate that the conformation of BSA has been subjected to alteration in presence of PSDF. The thermodynamic parameters namely ΔH, ΔG, ΔS were calculated at different temperatures (20 o C, 30 o C, and 40 o C) and the results indicated van der Waals force and hydrogen bonding were predominantly present. The compound PSDF also found to exhibit antifungal activity against Aspergillus sp. In addition, the results obtained from molecular modeling calculation vividly elucidate the binding mode and the binding sites and results were not well in agreement with the experimental observations.