A. Jagadesan; N. Sivakumar; R. Thinesh Kumar; S. Arjunan
Abstract
Crystal engineers have focused to control the solid structures though electrostatic, charge transfer, hydrogen bonding interactions. In particular, organic crystals have very good device oriented characteristics like optical response and large optical polarizability for nonlinear optical applications. ...
Read More
Crystal engineers have focused to control the solid structures though electrostatic, charge transfer, hydrogen bonding interactions. In particular, organic crystals have very good device oriented characteristics like optical response and large optical polarizability for nonlinear optical applications. In this point of view, we have concentrated on the growth of Benzimidazole benzimidazolium picrate crystal by cost effective solution growth method. The specimen has been subjected to different characterization studies. The single crystal XRD confirms the triclinic crystal structure (P-1) and both linear and nonlinearity of the materials have been analysed through UV-visible and SHG studies. Molecular vibrations, polarisational vibrations and presence of various functional groups present in the material have been identified through FTIR and FT-Raman spectral studies. The high intense light radiation test was performed on the crystal and it was estimated to be 1.39 GW/cm2. Copyright © VBRI Press.
A Shalini; P. Paulraj; k. Pandian; G. Anbazhagan; V. Jaisankar
Abstract
Synthesis of graphene oxide has entice good dispense of consciousness due to their vast utilization in different fields in modern days. In the present investigation, we report on the preparation of graphene oxide via a modified Hummer’s method. The nanocomposite were isolated and then characterized ...
Read More
Synthesis of graphene oxide has entice good dispense of consciousness due to their vast utilization in different fields in modern days. In the present investigation, we report on the preparation of graphene oxide via a modified Hummer’s method. The nanocomposite were isolated and then characterized by using various analytical techniques to understand the composition and the surface morphology of the nanocomposites. The structure as well as morphology of the nanocomposites were analyzed using SEM Instruments. The electro chemical behavior of the compound was studied by cyclic voltammetry in various supporting electrolyte. The electrocatalytic behavior of the nanocomposites monitored over the oxidation of nitric oxide (NO). Copyright © VBRI Press.
Gyanendra K. Pandey; Nilesh K. Pathak; R. P. Sharma
Abstract
Optical properties of Au metal nanoparticle have been studied in terms of extinction (scattering+absorption) at the resonance wavelength from UV to IR region. For the spherical geometry having radius 10nm, local electric field intensity distribution were studied at wavelength 615nm. This enhanced field ...
Read More
Optical properties of Au metal nanoparticle have been studied in terms of extinction (scattering+absorption) at the resonance wavelength from UV to IR region. For the spherical geometry having radius 10nm, local electric field intensity distribution were studied at wavelength 615nm. This enhanced field has been couples in the SERS where we increase the sensitivity of the surface to detect a single biomolecule which is adsorbed at the surface of metal nanoparticle. The field profile was studied using COMOL-5.2 which works on the principle of electrodynamics in which the solution of Maxwell’s equation with certain boundary condition is solved. Optimized physical and geometrical parameters was suggested for the application in the field of chemical and biomedical instrument development for the purpose of drug detection and disease diagnosis for cancer detection at the early stage. Copyright © 2018 VBRI Press.
Amit Srivastava; Naresh Kumar
Abstract
Biosensor for the detection of hydrogen peroxide (H2O2) has been prepared by immobilizing horseradish peroxidase (HRP) enzyme using physical adsorption technique on zinc oxide (ZnO) nanostructures. The (002) oriented ZnO nanostructures as confirmed by X-ray diffraction, were successfully grown on indium ...
Read More
Biosensor for the detection of hydrogen peroxide (H2O2) has been prepared by immobilizing horseradish peroxidase (HRP) enzyme using physical adsorption technique on zinc oxide (ZnO) nanostructures. The (002) oriented ZnO nanostructures as confirmed by X-ray diffraction, were successfully grown on indium tin oxide (ITO) coated glass substrate by pulsed laser ablation (PLA) without using any catalyst. The Nafion solution was added onto HRP/ ZnO/ ITO bio-electrode to form a tight membrane on the surface before carrying out bio-sensing measurements by electrochemical analyzer. The electrochemical studies reveal that the prepared bio-electrode HRP/ZnO/ITO is highly sensitive to the detection of H2O2 over a wide range of concentration with a linear range from 2.5 μM to 100 μM with the limit of detection 0.2 μM and sensitivity of 0.034 µA/ µM cm2. The higher sensitivity attributed to larger surface area of ZnO nanostructure for effective loading of HRP besides its high electron communication capability. A relatively low value of the enzyme’s kinetic parameter (Michaelis-Menten constant, Km) of 0.166 μM indicates enhanced enzyme affinity of HRP to H2O2. The reported biosensor may be useful for various applications in bio-sensing, clinical, food and beverage industry.
Hiranand R. Khambayat; Pravin S. More; Bandoba T. Nikam
Abstract
In this manuscript we have investigated the fabrication of PEO embedded planar optical waveguide (POW) sensor. To improve the sensing characteristics of POW, it has coated with conducting polymer poly ethylene oxide (PEO). The embedded waveguide prepared with variant thermal ion exchange process with ...
Read More
In this manuscript we have investigated the fabrication of PEO embedded planar optical waveguide (POW) sensor. To improve the sensing characteristics of POW, it has coated with conducting polymer poly ethylene oxide (PEO). The embedded waveguide prepared with variant thermal ion exchange process with various time duration of 20,40,60,80,100,120 minutes on sodium silicate glass. The properties of modified planar optical waveguideenhance the sensing activity, which can help to study the characteristics of soil by doping of different fertilizerswith x wt% (x=1, 2, 3, 4, 5) of varying concentrations. The use of appropriate percentage of fertilizer in differentsoil yield good healthy crop. The laser technique is used to study the POW for characteristics of soil. The material characterization study done by scanning electron microscopy (SEM) and small angle X-ray diffraction (XRD) revealed the formation of K+ ions layer in surface-near regions of the sample at optimum expose time period of 120 minutes at 380 0C. It gives an advantageous application for unidentified soil character analysis. Copyright © 2017 VBRI Press.
Subhash Nimanpure; S. A. R. Hashmi; Rajnish Kumar; Archana Nigrawal; H.N. Bhargaw; Ajay Naik
Abstract
Environment friendly electrical insulation material was developed using bio based rectangular cross sectioned sisal fibrils as reinforcement. High content cellulose base fibrils fibrillated by mechanical disintegration method into macro and micro fibrils from coarse sisal fibre. This fibrils were randomly ...
Read More
Environment friendly electrical insulation material was developed using bio based rectangular cross sectioned sisal fibrils as reinforcement. High content cellulose base fibrils fibrillated by mechanical disintegration method into macro and micro fibrils from coarse sisal fibre. This fibrils were randomly distributed in polymer matrix. These composites were characterized in term of electrical, mechanical and thermal properties to investigate the stability for high strength electrical insulation materials. Excellent mechanical properties were observed. Tensile, flexural and impact strength of composites at 40 wt. % fibril loading improved by 151.34, 197.43 and 360.07 % as compared to unsaturated polyester resin. A few micro-mechanical models were compared with the experimental values. Nielson-Chen Model predicted the experimental data most accurately. The electrical properties of surface modified sisal fibril composites improved significantly in higher frequency. DSC analysis showed that the decomposition temperature of composite was higher, around 22°C than that of the polyester resin. Thermal degradation reduced and was observed in the range of 83-87% of fibril composites as compared to 97% of resin. Fibril composites are highly sensitive to electrical frequency and exhibit excellent electrical insulation property at 20 kHz. Alkali treated fibril based composites resulted an environment friendly thermally stable, high strength insulation material. Copyright © 2018 VBRI Press.
Yana Bagbi; Ankur Sarswat; Sachchidanand Tiwari; Dinesh Mohan; Arvind Pandey; Pratima R. Solanki
Abstract
Zero-valent iron nanoparticles (NZVI) were synthesized using chemical reduction method. These were applied for lead removal from water. The structural, morphological, compositional and optical studies were studied out using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic ...
Read More
Zero-valent iron nanoparticles (NZVI) were synthesized using chemical reduction method. These were applied for lead removal from water. The structural, morphological, compositional and optical studies were studied out using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering, scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR). The NZVI optical energy band gap as calculated by UV absorption spectrum was 1.7 eV. The zeta potential was obtained as -32.0 mV. The biocompatibility test of NZVI was performed using MTT assay on MDCK-2 as model cell lines. Lead adsorption on NZVI was examined at different pHs, equilibrium time, temperature, and NZVI/Pb2+ concentrations. Almost 100% Pb2+ removal was achieved at NZVI dose: 0.4 g/L;Pb2+ concentration: 50 mg/L; equilibrium time: 15 min; pH 5-6; and temperature: 25°C. Pb2+ sorption kinetic data were fitted to pseudo-first and second-order kinetic equations. Pseudo-second-order kinetic equation best fitted the data. These studies clearly demonstrate NZVI as an efficient nano-adsorbent for Pb2+ removal from water. Copyright © 2017 VBRI Press
Shobhna Choudhary; Ram J. Sengwa
Abstract
The dielectric and electrical spectra of solution cast prepared nanocomposite films comprising poly(vinyl alcohol) (PVA) as polymer matrix and zinc oxide (ZnO) as inorganic nanofiller (PVA–x wt% ZnO (x = 0, 1, 3 and 5)) have been investigated in the frequency range from 20 Hz to 1 MHz. Anomalous ...
Read More
The dielectric and electrical spectra of solution cast prepared nanocomposite films comprising poly(vinyl alcohol) (PVA) as polymer matrix and zinc oxide (ZnO) as inorganic nanofiller (PVA–x wt% ZnO (x = 0, 1, 3 and 5)) have been investigated in the frequency range from 20 Hz to 1 MHz. Anomalous increase is observed in real part of complex permittivity with increase of ZnO concentration, whereas relaxation peak corresponding to PVA chain segmental motion is appeared in the intermediate frequency region of dielectric loss tangent and the loss part of electric modulus spectra of the nanocomposites. These results confirm that the interaction of ZnO nanoparticles with hydroxyl groups of PVA acts as exciter for polymer chain segmental dynamics in the nanocomposites. The temperature dependent dielectric investigations on PVA–3 wt% ZnO film reveal that the dielectric polarization and chain segmental dynamics increase with the increase of temperature. The dielectric relaxation and conductivity activation energies values of the film are determined from the Arrhenius relation, which are found equal. The X-ray diffraction study confirms that the crystalline phase of PVA matrix abruptly reduces with doping of only 1 wt% ZnO which suggests that the interaction of polymer-nanoparticles significantly alter the hydrogen bonded crystalline structure of pristine PVA matrix. The dielectric and electrical results showed that these nanodielectrics are potentially useful as an electrical insulation material for various electronic devices. Copyright © 2017 VBRI Press.
I.N.G. Wardana
Abstract
This study aims to utilize of bio material to produce green hydrogen energy through hybrid of the activated carbon and the CuO catalyst in vegetable oil steam reformer. The experiment was done in the atmospheric pressure steam reformer. The results show that activated carbon and CuO individually performs ...
Read More
This study aims to utilize of bio material to produce green hydrogen energy through hybrid of the activated carbon and the CuO catalyst in vegetable oil steam reformer. The experiment was done in the atmospheric pressure steam reformer. The results show that activated carbon and CuO individually performs the same trend in producing hydrogen. Their combination accelerates hydrogen production. This indicates that heat energy makes CuO alters the electron density around the reactant by combining the van der Waals force with the induction due to electron jump in its narrow ban gap. Therefore, CuO activate effectively the polar water (H2O) molecules. More energy is needed to alter the electron in stable large molecule triglyceride of vegetable oil. On the other hand, the activated carbon does it by combining the van der Waals force with the induction due to delocalized of the pi electrons travelling between carbon atoms in the graphite structure. Consequently, only the nonpolar triglyceride molecules are attracted while the polar H2O are repelled by hydrophobic force. Thus, larger energy is needed to activate electrons in H2O. When they are combined, the CuO works only on H2O while activated carbon does only on triglyceride which is highly effective. Copyright © 2018 VBRI Press.
Sunny Anand; S. Inthekhab Amin
Abstract
In this work, the charge plasma based dual electrode doping-less tunnel FETs (DEDLTFET) is simulated with the use of different materials such as silicon (Si-DEDLTFET), Silicon-germanium (SiGe-DEDLTFET) and SiGe at Source (SiGe Source DEDLTFET). The charge plasma technique is used to create source and ...
Read More
In this work, the charge plasma based dual electrode doping-less tunnel FETs (DEDLTFET) is simulated with the use of different materials such as silicon (Si-DEDLTFET), Silicon-germanium (SiGe-DEDLTFET) and SiGe at Source (SiGe Source DEDLTFET). The charge plasma technique is used to create source and drain region on an intrinsic body by selecting appropriate work function of metal electrode. The paper provides the comparison among devices on the basis of RF parameters. The on-state current (ION) for SiGe source DEDLTFET, SiGe-DEDLTFET and DEDLTFET are 1.84x10-4, 8.75x10-5 and 8.11x10-6 A/µm respectively for similar off-state current (IOFF). This result show that SiGe source DEDLTFET device provides better drive current along with improved ON-OFF current ratio (ION/IOFF) and subthreshold slope (SS). Improved transconductance (gm) and cut-off frequency (fT) show that the hetero-material device has better RF performance while comparing with the other two devices. Copyright © 2017 VBRI Press.
Joel Espino-Portillo; Dora A. Cortés-Hernández; José C. Escobedo-Bocardo; Héctor J. Sánchez; Mirna M. G. Saldívar-Ramírez; Laura E. De-León-Prado
Abstract
The effect of mixed ferrites nature and that of several coatings on the magnetic properties and thus, on the heating ability of nanoparticles, was studied. The Mg0.4Ca0.6Fe2O4 and Mn0.5Ga0.5Fe2O4 ferrites, synthesized by sol-gel method, followed by heat treatment, were coated with oleic acid + Pluronic® ...
Read More
The effect of mixed ferrites nature and that of several coatings on the magnetic properties and thus, on the heating ability of nanoparticles, was studied. The Mg0.4Ca0.6Fe2O4 and Mn0.5Ga0.5Fe2O4 ferrites, synthesized by sol-gel method, followed by heat treatment, were coated with oleic acid + Pluronic® F-127, carboxymethyl-dextran sodium or polyvinylpyrrolidone. An average particle size of 12 and 15 nm was obtained for the Mg-Ca and Mn-Ga ferrites, respectively. Samples, before and after coating, revealed a heating capacity over 42°C and a superparamagnetic behaviour. The compounds accomplished the requirements of heating ability and specific absorption rate for magnetic hyperthermia treatment. The Mn0.5Ga0.5Fe2O4 system was more efficient than the Mg0.4Ca0.6Fe2O4 system. Copyright © 2018 VBRI Press.
Yesappa L; Niranjana M; Sharanappa Chapi; Archana K.; Raghu S.; Devendrappa H
Abstract
Bio-intercalation based Polyaniline (PANI)-Aloe vera (AV) with Lithium Perchlorate (LiClO4) composites has been synthesized by In-situ chemical reaction method. The composite was employed characterizations with help of Fourier Transform Infrared (FT-IR) Spectroscopy and Scanning Electron Microscopy (SEM) ...
Read More
Bio-intercalation based Polyaniline (PANI)-Aloe vera (AV) with Lithium Perchlorate (LiClO4) composites has been synthesized by In-situ chemical reaction method. The composite was employed characterizations with help of Fourier Transform Infrared (FT-IR) Spectroscopy and Scanning Electron Microscopy (SEM) to know the chemical interaction and morphology of the composites. From SEM result it was noticed that morphology became changes significantly with reduce porosity. The Ultra Violet Absorption (UV-Vis) study shows that absorption increases as well as maximum peak shifts and PAL10 red shifts in visible region at 615nm. These results manifest that PANI-AV/LiClO4 (PAL) composites are the promising materials for solar cell, LED’s and electrical applications. Copyright © 2017 VBRI Press
P. Neelima; S. R. Murthy
Abstract
Microwave-hydrothermal (M-H) method had been employed to synthesize a series of Dy3+doped Mn-Zn ferrite Mn0.6Zn0.4Fe2–xDyxO4 (x=0, 0.01, 0.03, 0.05, 0.07, 0.09) nanopowders at 160°C/30 min. The prepared samples have been characterized by Fourier Transform Infrared Spectrometer. The grain size ...
Read More
Microwave-hydrothermal (M-H) method had been employed to synthesize a series of Dy3+doped Mn-Zn ferrite Mn0.6Zn0.4Fe2–xDyxO4 (x=0, 0.01, 0.03, 0.05, 0.07, 0.09) nanopowders at 160°C/30 min. The prepared samples have been characterized by Fourier Transform Infrared Spectrometer. The grain size of sintered ferrites are in the range of 60-70 nm. Decrease in saturation magnetization and increase in coercivity were observed with an increase of Dy3+ concentration in Mn-Zn ferrites. The complex permeability and complex permittivity of the prepared samples were measured in the frequency range of 2–18 GHz using a using a vector network analyzer. It is observed that small variation of Dy3+ substitution in spinel ferrite tailored microwave absorbing parameters dramatically. The reflection loss (RL) increased with the Dy3+ content upto x ≤ 0.03. The sample with x=0.03 of thickness 2.3 mm showed minimum reflection loss of -20.5 dB with a bandwidth of 3.8 GHz. Thus the present materials exhibit good microwave absorption properties and hence can act as EMI suppressors. Copyright © 2018 VBRI Press.
Shivani A. Singh; Pravin. S. More; Dattatray. J. Late; Rajesh W. Raut
Eva Kormanikova; Kamila Kotrasova
Abstract
This paper deals with numerical modelling of laminate composite plate delamination that consists of unidirectional fiber reinforced layers. The delamination may be a fundamental problem in design of composite structures. The first-order shear laminate plate theory and fracture and contact mechanics were ...
Read More
This paper deals with numerical modelling of laminate composite plate delamination that consists of unidirectional fiber reinforced layers. The delamination may be a fundamental problem in design of composite structures. The first-order shear laminate plate theory and fracture and contact mechanics were adopted for the methodology. The sublaminate modelling and delamination modelling are described by the help of finite element analysis. The displacements, reaction forces in springs and energy release rate along the lamination front are computed in modelling of interface. The numerical results are presented for problems with delamination of the mixed mode by using of 2D finite element analysis in the commercial ANSYS software. Copyright © 2018 VBRI Press.
Syed Gulraze Anjum; Aboo Bakar Khan; Mohammad Jawaid Siddiqui; Parvez Ahmad Alvi
Abstract
In this article, we have computationally analyzed the Type-I InGaAsN/GaAs (dilute N) material system based step-index separately confined heterostructure (STINSCH) consisting of a compressively strained single quantum well layer. The whole structure is assumed to be grown on GaAs substrate. The optical ...
Read More
In this article, we have computationally analyzed the Type-I InGaAsN/GaAs (dilute N) material system based step-index separately confined heterostructure (STINSCH) consisting of a compressively strained single quantum well layer. The whole structure is assumed to be grown on GaAs substrate. The optical gain spectra have been calculated and compared for single quantum well structure for the two different carrier densities under TE and TM polarization modes at room temperature. The size of the STINSCH based nano-scale heterostructure taken as a whole including SQW together with barriers and claddings is 47nm. In order to validate the computed optical gain, the anti-guiding factor has also been evaluated for the same nano-heterostructure. The GAIN software package has been utilized to obtain the various lasing properties like optical gain, modal gain, and anti-guiding factor. Therefore, this lasing nano-heterostructure may found application in optical fiber communication systems as a light source because of less attenuation and minimum optical loss. Copyright © 2018 VBRI Press.
Swati Mamgain
Abstract
The structural, optical and electrical aspects of as deposited as well as annealed amorphous hydrogenated silicon nitride(a-SiNx: H) thin films of different stoichiometry, grown on silicon wafer by radio frequency- plasma enhanced chemical vapor deposition (RF-PECVD) are thoroughly investigated. Photoluminescence ...
Read More
The structural, optical and electrical aspects of as deposited as well as annealed amorphous hydrogenated silicon nitride(a-SiNx: H) thin films of different stoichiometry, grown on silicon wafer by radio frequency- plasma enhanced chemical vapor deposition (RF-PECVD) are thoroughly investigated. Photoluminescence (PL) measurement verify that Si rich a-SiNx: H (SRSN) film of refractive index 2.68, gives good PL as compared to near stoichiometric film and support the presence of Silicon quantum dots (Si QDs) embedded in a-SiNx: H matrix. Detailed structural analysis by high resolution transmission electron microscopy (HRTEM) revealed that as deposited SRSN thin film contains amorphous Silicon quantum dots (a-Si QDs) which are grown by phase separation of SRSN film during the synthesis process. These SRSN thin films of different thicknesses have been deposited at the surface of Silicon solar cell as anti-reflection coatings (ARCs). By reflectance measurement, it is observed that the ARC contains a-Si QDs in a-SiNx: H matrix, more effectively minimize the reflection of incident light across the wavelengths ranging from 300 to 800 nm. With a-Si QDs/ a-SiNx: H ARC, we demonstrate an increase in short circuit current density, open circuit voltage and conversion efficiency by 4.34 mA/cm2, 0.01V and 0.21% (absolute) respectively and indicate its utility in improving the performance of Si solar cells. Copyright © 2017 VBRI Press.
Arehalli S Santhosh; Shadakshari Sandeep; Ningappa Kumara Swamy; Gurukar S Suresh; Jose S Melo
Abstract
In the present work, we report on green synthesis of hybrid silver nano structures using a solution of AgNO3 and leaf broth of Cassia occidentalis plant as reducing agent. The incubation of AgNO3 solution and leaf broth for 48 hrs under neutral pH and constant stirring at 150 rpm resulted in the formation ...
Read More
In the present work, we report on green synthesis of hybrid silver nano structures using a solution of AgNO3 and leaf broth of Cassia occidentalis plant as reducing agent. The incubation of AgNO3 solution and leaf broth for 48 hrs under neutral pH and constant stirring at 150 rpm resulted in the formation of hybrid silver nanostructures comprised of silver nano particles (AgNPs) and silver nanorods (AgNRs). The bio reduction of Ag+ ions to AgNPs and AgNRs is confirmed via appearance of surface plasmon resonance peaks at 420 and 370 nm in the UV visible spectrum. The synthesized nanostructures are purified and further characterized using XRD and FT-ATR. The morphology of nanostructures is examined by SEM studies which further revealed the formation of spherical shaped AgNPs and rod shaped AgNRs. The study therefore concludes that it is possible to synthesize the AgNRs and AgNPs effectively using silver nitrate (AgNO3) solution and the leaf broth of Cassia occidentalis. However, further work is needed to establish the employability of these nanostructures in various applications. Copyright © 2017 VBRI Press.
Hitesh R. Ashani; Sachin P. Parikh; Jaysukh H. Markna
Abstract
Nanotechnology is considered as one of the active research area of 21st century due to its increasing economic importance and ability to study the material at nano scale to improve its behavior in construction industry. Concrete the second highest consume commodity on the planet after water is highly ...
Read More
Nanotechnology is considered as one of the active research area of 21st century due to its increasing economic importance and ability to study the material at nano scale to improve its behavior in construction industry. Concrete the second highest consume commodity on the planet after water is highly heterogeneous material with thumping performance challenges on it. Demand of concrete is increasing due to increasing demand for infrastructure development, rapid urbanization, rapid industrial development, population growth, economic development of the nation etc. A little diminution in the number of problems related with concrete would add up to noteworthy recital enhancement and economic benefits to society and nation. In the present communication, the cement one of the main ingredient of concrete was replaced with a range of5%, 10%, 15% and 20 % of the weight of cement by nano carbon material to study the effect on the mechanical properties like – compressive strength, surface hardness, water absorption, consistency, morphology on nano carbon concrete specimen. A rapport was made between standard and nano carbon black concrete specimen to arrive at a legitimate conclusion that improvement in the mechanical properties like strength, hardness, compactness etc. and C-S-H gel structure is obtained. Copyright © 2017 VBRI Press.
Zdeněk Prošek; Jan Trejbal; Pavel Tesárek; Lubomír Kopecký
Abstract
This work deals with a utilization of a plasma treatment of polymeric macro-fibers used as reinforcement in the cement composites. Commercial fibers BeneSteel were plasma treated to reduce their weaknesses – smooth and chemically inert surfaces and thus to enhance an interfacial shear strength ...
Read More
This work deals with a utilization of a plasma treatment of polymeric macro-fibers used as reinforcement in the cement composites. Commercial fibers BeneSteel were plasma treated to reduce their weaknesses – smooth and chemically inert surfaces and thus to enhance an interfacial shear strength between them and the cement matrix. The low-pressure cold oxygen plasma treatment was done for both physical (roughening) and chemical (surface activation via active polar groups) surface modifications. A plasma exposition time differed between 5 and 480 seconds, while the surface changes were observed. It was shown that the most effective treatment time was equal to 30 seconds, as proven by a wettability measurement between fibers and demineralised water. To determine the interfacial shear strength between reference and chosen modified fibers, pull out tests from the cement matrix was performed. Finally, thus treated fibers were used as the reinforcement in concrete composites. Concrete samples having dimension equal to 100 × 100 × 400 mm were tested in the three-point bending test. We focused especially on the post-cracking response of tested samples. The results showed that the post-cracking residual flexural strength of samples reinforced with plasma treated fibers was higher by 30 %. It was find out that the utilization of plasma treated fibers is more effective if compared to reference ones. Copyright © 2017 VBRI Press.
Trupti Kekare; Dhananjay Bhatkhande; Tanushree Bhattacharjee; Shraddha Khamparia
Abstract
Microbial contamination in drinking water proves to be a sustainable threat to human health. Several methods are being utilized for disinfecting contaminated drinking water varies from simple boiling method to advanced technologies such as membrane technologies (Micro filtration, Ultra filtration, Reverse ...
Read More
Microbial contamination in drinking water proves to be a sustainable threat to human health. Several methods are being utilized for disinfecting contaminated drinking water varies from simple boiling method to advanced technologies such as membrane technologies (Micro filtration, Ultra filtration, Reverse osmosis). Various chemical methods practiced are chlorination, ozone, hydrogen peroxide, iodine, bromine, and peracetic acid treatment. Chemical disinfectants lead to formation of toxic by-product which degrade the quality of water. The present review paper discusses alternative methods for chemical disinfection of potable water.
M. Priya; k. Sathyamoorthy; p. Vinothkumar; Ro. Mu. Jauhar; p. Murali Manohar; A. Selvam
Abstract
The Mannitol single crystal was grown by slow evaporation technique and irradiated by gamma radiation. Single crystal XRD analysis showed that irradiation not changed the crystal system. The crystalline perfection of pure and irradiated Mannitol single crystal were studied by high resolution X-ray diffraction ...
Read More
The Mannitol single crystal was grown by slow evaporation technique and irradiated by gamma radiation. Single crystal XRD analysis showed that irradiation not changed the crystal system. The crystalline perfection of pure and irradiated Mannitol single crystal were studied by high resolution X-ray diffraction analysis. The optical behaviour of pure and irradidated Mannitol was verified by the changes in the affected cut-off wavelength. The laser damage threshold was calculated for pure and irradiated Mannitol using laser source. The second harmonic generation of pure and gamma irradiated Mannitol were studied using Nd:YAG laser source and observed that SHG intensity decreases with increasing dose of gamma radiation.
Azizurrahaman Ansari; Vishal Kumar Chakradhary; M. J. Akhtar
Abstract
In this article, an effort is made to synthesize the nickel ferrite nanoparticles via chemical co-precipitation method using the metal nitrates as precursors. The x-ray diffraction pattern of the as-synthesized powder sample indicates the formation of nickel ferrite with iron oxide and other impurity ...
Read More
In this article, an effort is made to synthesize the nickel ferrite nanoparticles via chemical co-precipitation method using the metal nitrates as precursors. The x-ray diffraction pattern of the as-synthesized powder sample indicates the formation of nickel ferrite with iron oxide and other impurity phases. The heat treatment of the as-synthesized powder at 600oC assists in the formation of inverse spinel phase of nickel ferrite accompanying with some fraction of iron oxide phase. The field emission scanning electron microscopy of the heat treated sample reveals the irregular particle size and shape with fine microstructures, while as-synthesized sample shows the lamina like particle morphology. The magnetization curve(M-H curve) of the heat treated sample shows the ferrimagnetic behavior with very small (negligible) values ofremanent magnetization and coercive field. Such type of magnetic characteristic indicates the signature of superparamagnetism (Mr ~ 0, Hc ~ 0) in the heat treated nickel ferrite nanoparticles with significant value of the saturation magnetization (Ms). The superparamagnetic effect in the nickel ferrite particles has great potential in the field of biomedicine for certain applications such as the effective drug delivery, and for enhancing the contrast in case of magnetic resonance imaging. Copyright © 2016 VBRI Press.
Santosh A. Mani; Sameer U. Hadkar; Jyoti R. Amare; Madhavi S. Pradhan; Hind Al-Johani; Pradip B. Sarawade
Abstract
In the present study, effect of CNT on optical and thermal properties of mixed thermotropic liquid crystal mixture was studied by various techniques to understand their physical behavior. Some new mesophases have investigated by optical methods viz. Polarizing Optical Microscopy (POM) and Fabry–Perot ...
Read More
In the present study, effect of CNT on optical and thermal properties of mixed thermotropic liquid crystal mixture was studied by various techniques to understand their physical behavior. Some new mesophases have investigated by optical methods viz. Polarizing Optical Microscopy (POM) and Fabry–Perot Scattering Studies (FPSS). It has been observed that these new phase transition occur along with the known phase transition temperatures. These new phase transitions corresponding to new mesophases were also confirmed by thermal study using Differential Thermal Analysis (DTA). The CNT doped thermotropic liquid mixtures can be used in various display application such as LCD monitor with color variation to enhance performance. Copyright © 2018 VBRI Press.
Lila A. Alkhtaby
Abstract
We have to study the factors affecting the synthesis of Co doping ZnO Nano powder with the sol – gel method to study the effect of quantity or doping concentration we fix the reaction base at pH = 9 and change the doping concentration the structural and morphology ...
Read More
We have to study the factors affecting the synthesis of Co doping ZnO Nano powder with the sol – gel method to study the effect of quantity or doping concentration we fix the reaction base at pH = 9 and change the doping concentration the structural and morphology carried out with X-ray and SEM show hexagonal wurtzite nanoparticles for Zn 1-x Co x O for x = 0.01 and x = 0.05 and increase of the cell volume and lattice parameter with increase of x concentration ,the florescence spectroscopy at room temperature show peaks at ultraviolet for both concentration with read shift for x = 0.05. To study the effect of pH value we fix doping concentration at x = 0.05, SEM shows a spherical nanoparticle with size 38 – 52 nm for pH = 9 and hexagonal nanoparticles with size 42 – 52 nm for pH = 6. The florescence spectroscopy at room temperature exhibit that for pH = 9 there is no band observed in the ultraviolet region bands are around 380,420 and 475 nm. The Ultraviolet/Visible (UV) Spectroscopy exhibit decrease of the band gap energy with increase doping concentration and decrease with increase pH value. Copyright © VBRI Press.
