Indian Journal of Materials Science The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Biosynthesis, Characterization, and Antidermatophytic Activity of Silver Nanoparticles Using Raamphal Plant (Annona reticulata) Aqueous Leaves Extract Tue, 08 Apr 2014 08:15:18 +0000 The present work investigated the biosynthesis of silver nanoparticles using Annona reticulata leaf aqueous extract. The biosynthesised silver nanoparticles were confirmed by visual observation and UV-Vis spectroscopy. Appearance of dark brown colour indicated the synthesis of silver in the reaction mixture. The silver nanoparticles were found to be spherical, rod, and triangular in shape with variable size ranging from 23.84 to 50.54 nm, as evident by X-ray diffraction studies, TEM. The X-ray diffraction studies, energy dispersive X-ray analysis, and TEM analysis indicate that the particles are crystalline in nature. The nanoparticles appeared to be associated with some chemical compounds which possess hydroxyl and carbonyl groups, confirmed by FTIR. This is the first and novel report of silver nanoparticles synthesised from Annona reticulata leaves extract and their antidermatophytic activity. P. Shivakumar Singh and G. M. Vidyasagar Copyright © 2014 P. Shivakumar Singh and G. M. Vidyasagar. All rights reserved. Water-Soluble and Biodegradable Pectin-Grafted Polyacrylamide and Pectin-Grafted Polyacrylic Acid: Electrochemical Investigation of Corrosion-Inhibition Behaviour on Mild Steel in 3.5% NaCl Media Mon, 07 Apr 2014 13:57:44 +0000 Pectin-g-polyacrylamide (denoted as Pec-g-PAAm) and pectin-g-polyacrylic acid (denoted as Pec-g-PAA) were synthesized using pectin, acrylamide, and acrylic acid as starting materials. The grafted polymers were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyser (TGA), and scanning electron microscopy (SEM). The corrosion inhibition behaviour of the grafted polymers on mild steel in 3.5% NaCl was evaluated electrochemically through Tafel polarization and impedance studies. The corrosion inhibition performance of both the polymers was found to be around 85%. R. Geethanjali, A. Ali Fathima Sabirneeza, and S. Subhashini Copyright © 2014 R. Geethanjali et al. All rights reserved. Ytterbium Doped Gadolinium Oxide (Gd2O3:Yb3+) Phosphor: Topology, Morphology, and Luminescence Behaviour Thu, 03 Apr 2014 12:47:56 +0000 Gd2O3:Yb3+ phosphor has been synthesized by the solid state reaction method with boric acid used as a flux. The resulting Gd2O3:Yb3+ phosphor was characterized by X-ray diffraction (XRD) technique, Fourier transmission infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM), and photoluminescence and thermoluminescence. The results of the XRD show that obtained Gd2O3:Yb3+ phosphor has a cubic structure. The average crystallite sizes could be calculated as 42.9 nm, confirmed by the TEM results. The study suggested that Yb3+ doped phosphors are potential luminescence material for IR laser diode pumping. Raunak Kumar Tamrakar, Durga Prasad Bisen, Chandra Shekher Robinson, Ishwar Prasad Sahu, and Nameeta Brahme Copyright © 2014 Raunak Kumar Tamrakar et al. All rights reserved. Adsorbent Ability of Treated Peganum harmala-L Seeds for the Removal of Ni (II) from Aqueous Solutions: Kinetic, Equilibrium and Thermodynamic Studies Thu, 27 Mar 2014 12:01:25 +0000 The main goal of this study was to evaluate the performance of new adsorbent, treated Peganum harmala-L seeds (TPHS), for the removal of Ni (II) from aqueous solution. Batch experiments were performed as a function of various experimental parameters. The adsorption studies included both equilibrium adsorption isotherms and kinetics. Equilibrium data fitted very well with the Langmuir isotherm model. Maximum adsorption capacity was determined 91.74 mg/g at pH 7. Kinetics studies showed better applicability for pseudo-second-order model for both adsorbents. The negative value of confirmed the feasibility and spontaneity of TPHS for Ni (II) adsorption. Maryam Ghasemi, Nahid Ghasemi, and Javad Azimi-Amin Copyright © 2014 Maryam Ghasemi et al. All rights reserved. Preparation of Samarium Doped Calcium Hydrogen Phosphate and Study of Its Density and Thermal and Dielectric Characteristics Mon, 24 Mar 2014 11:58:00 +0000 Samarium doped calcium hydrogen phosphate was synthesized as single crystal by room temperature solution growth technique, namely, silica gel technique. The kinetics of the growth parameters was studied with regard to variation of pH, dopant concentration, gel ageing, and upper reactant concentration. The optimum conditions for the growth of good quality single crystal were worked out. Single crystal X-ray diffraction analysis establishes that the crystal belongs to monoclinic system. The density observed by the flotation method is greater than the density of the reported pure calcium hydrogen phosphate thereby suggesting the incorporation of the dopant (Sm) ion into the lattice of host (CHP). Thermal analysis gave two sharp endothermic peaks which are due to partial dehydration and phase transition, respectively. Dielectric studies establish a shift in the Curie temperature from 355 to 370°C only at higher frequencies thereby suggesting the relaxational behavior of the material. K. K. Bamzai, Goldy Slathia, Bindu Raina, Rashmi Gupta, Seema Verma, Shivani Suri, and Vishal Singh Copyright © 2014 K. K. Bamzai et al. All rights reserved. Variations of Optical and Structural Properties of Thin Films with Thermal Treatment Wed, 12 Mar 2014 08:01:21 +0000 The effects of thermal treatment on the optical and structural properties of cobalt oxide thin films synthesized in the pores of PVP by chemical bath deposition technique were investigated. Films deposited were crystalline. The optical properties of the films were got from absorbance, transmittance reflectance, refractive index, absorption coefficient, and extinction coefficient measurements. The synthesized films turned out to be cobalt oxyhydroxide , CoO(OH), nanocrystals. The crystals obtained were of size 41.84 nm; however, as annealing temperature increased, the size decreased to 16.28 nm. The absorption coefficient, refractive index, and extinction coefficient were found to increase with increase in annealing temperature though not sequentially. For the same energy ranges of the incident photons, the absorption coefficient and refractive index ranged from 0.2 to 1.8 and from 1.4 to 2.3, respectively. The energy band-gap of the films ranged from 1.96 eV to 2.22 eV. A. B. C. Ekwealor, S. U. Offiah, S. C. Ezugwu, and F. I. Ezema Copyright © 2014 A. B. C. Ekwealor et al. All rights reserved. The Role of Polarons in Cuprates Hi- Superconductivity Mon, 10 Mar 2014 00:00:00 +0000 The phonon contribution to the phenomenon of high temperature superconductivity in the cuprates is argued as being masked as polarons generated by the polarization of the charge reservoir accompanying the Jahn-Teller tilting of the apical oxygen. We discuss the Mahan oscillator-spring extension model as an analogy to the charge reservoir-CuO plane -axis polarons. Using the Boltzmann kinetic equation, we show that the polaron dissociates or collapses at a temperature corresponding to the critical temperature of the superconductor. M. I. Umo Copyright © 2014 M. I. Umo. All rights reserved. Visible Light Photocatalytic Activity of CeO2-ZnO-TiO2 Composites for the Degradation of Rhodamine B Mon, 03 Mar 2014 09:22:34 +0000 TiO2 plays a significant role in many applications including solar cell. Consecutively to absorb the low-energy radiation, it is very much essential to tune the optical property of TiO2. We fabricated CeO2-ZnO-TiO2 semiconductor composites by sol-gel method and achieved the absorption of lower energy radiation. The prepared composites were characterized by TG-DTA, UV-DRS, XRD, AFM, TEM and FESEM techniques. The particle and crystalline size of the composites was calculated using FESEM and XRD techniques, respectively. The photocatalytic activity of the synthesized composite for the degradation of Rhodamine B (RhB) under visible light irradiation was investigated. The photocatalytic degradation of RhB under various experimental conditions such as amount of catalyst, initial dye concentration and H2O2 amount was also demonstrated and the rate constant was calculated using L-H model. S. Prabhu, T. Viswanathan, K. Jothivenkatachalam, and K. Jeganathan Copyright © 2014 S. Prabhu et al. All rights reserved. Microstructure Properties of Rapidly Solidified Al-Zn-Mg-Cu Alloys Sun, 02 Mar 2014 00:00:00 +0000 The Rietveld X-ray diffraction analysis was applied to analyze the weight fraction of precipitation phases and microstructure characterizations of rapidly solidified Al-8Zn-4Mg-Cu, = 1, 4, 8, and 10 alloys (in wt.%), prepared by melt spun technique. A good agreement between observed and calculated diffraction pattern was obtained and the conventional Rietveld factors (, , and GOF) converged to satisfactory values. Solid solubilities of Zn, Mg, and Cu in α-Al were extended to high values. Besides, metastable Al0.71Zn0.29, intermetallic Al2CuMg, Al2Cu, and CuMgZn phases have been observed for = 4, 8, and 10 Cu alloys. The crystal structure and microstructure characterizations exhibit strong Cu content dependence. Emad M. Ahmed Copyright © 2014 Emad M. Ahmed. All rights reserved. Second Harmonic of Laser Radiation for IR-Range in Mixed Crystals Thu, 27 Feb 2014 07:50:32 +0000 The results of investigations of the influence of different parameters on conversion efficiency in mixed AgGa0.6In0.4Se2 crystal in conditions of existing experiments are cited. The angular dispersion coefficients for three versions of crystal , differing by a content of indium, have been calculated. A comparison was made of the obtained results on conversion efficiency with analogous results in case of other crystals and with corresponding experimentally measured values. The applied analytical method makes it possible to calculate the optimum parameters of both crystal-converter and a source of radiation for conditions of uncritical phase matching in the concrete experiment. Rena J. Kasumova Copyright © 2014 Rena J. Kasumova. All rights reserved. A Promising Orange-Red Nanocrystalline Potassium Lanthanum Orthophosphate for White Light-Emitting Diodes Wed, 19 Feb 2014 07:59:27 +0000 The spectral properties of the K3La(PO4)2:Eu3+ nanophosphors synthesized by the combustion method are reported. The phosphors were characterized by X-ray diffraction, transmission electron microscopy, and optical spectroscopy. The XRD pattern reveals a pure monoclinic phase of the K3La(PO4)2 with the average particle size of 30 nm in diameter. Under UV excitation, the phosphors exhibited several emission bands which were assigned to 4f-4f transitions of Eu3+ ions. The red shade of the Eu3+ ion with the CIE coordinates (x, y) as (0.63, 0.37) suggests that this material is a promising phosphor for near-UV InGaN-based LED lighting. Palvi Gupta, A. K. Bedyal, Vinay Kumar, Y. Khajuria, O. M. Ntwaeaborwa, and H. C. Swart Copyright © 2014 Palvi Gupta et al. All rights reserved. Kinetics of Thermolysis of Nickel(II) Perchlorate Complex with n-Propylamine Wed, 19 Feb 2014 07:36:09 +0000 Complex of nickel perchlorate with n-propylamine has been synthesised with molecular formula [Ni(n-pa)3(ClO4)(H2O)]ClO4. It has been characterised by elemental analysis, thermogravimetry, UV-VIS, and IR spectroscopic data. Thermal properties have been investigated by thermogravimetry (TG) in static air and by simultaneous thermogravimetry-derivative thermogravimetry-differential thermal analysis (TG-DTG-DTA) in flowing nitrogen atmosphere. Kinetics of thermolysis has been analysed applying model-fitting and model-free isoconversional method on isothermal TG data recorded at five different temperatures. To observe the response of complex towards fast heating, explosion delay time has been recorded at various temperatures and kinetics of explosion has been studied using these data. Chandra Prakash Singh and Abhishek Singh Copyright © 2014 Chandra Prakash Singh and Abhishek Singh. All rights reserved. Optimum Material Gradient for Functionally Graded Rectangular Plate with the Finite Element Method Mon, 17 Feb 2014 14:12:29 +0000 The optimum material gradient of a rectangular plate made of functionally graded material (FGM) is determined in this study. Elastic modulus of functionally graded (FG) rectangular plate is assumed to vary continuously throughout the height of the plate, according to the volume fraction of the constituent materials based on the power law, exponential model I, exponential model П, or sigmoid functions. The difference between these distribution functions for the constituents’ volume fraction is discussed in this study. To determine the optimum material gradient of a rectangular plate made of FGM, the finite element method and the optimization techniques are used. In this study, von Mises stress, shear stress, and deformation in FGM case with the power law, exponential model I, exponential model П, or sigmoid functions are investigated. Simulation results indicate that the optimum material gradient for FG rectangular plate can be described by using a modified sigmoid function. The maximum values of von Mises stress, shear stress, and deformation in FG rectangular plate with the optimum material gradient are reduced compared with the pure material case by around 22%, 11%, and 24%, respectively. Wasim M. K. Helal and Dongyan Shi Copyright © 2014 Wasim M. K. Helal and Dongyan Shi. All rights reserved. Effect of Eu3+ Concentration on Luminescence Studies of Y4Al2O9 Phosphor Thu, 13 Feb 2014 14:00:16 +0000 The present paper reports the effect of europium concentration on photoluminescence (PL) and thermoluminescence (TL) studies of Eu3+ doped Y4Al2O9 phosphor using inorganic materials like yttrium oxide (Y2O3), aluminium oxide (Al2O3), boric acid (H3BO3) as a flux, and europium oxide (Eu2O3). The sample was prepared by the modified solid state reaction method, which is the most suitable for large-scale production. The prepared phosphor sample was characterized using X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEGSEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL), thermoluminescence (TL), and CIE techniques. The PL emission was observed in the range of 467, 535, 591, 611, 625, and 629 nm for the Y4Al2O9 phosphor doped with Eu3+ (0.1 mol% to 2.5 mol%). Excitation spectrum was found at 237 and 268 nm. Sharp peaks were found around 591, 611, and 625 nm with high intensity. From the XRD data, using Scherer’s formula, the calculated average crystallite size of Eu3+ doped Y4Al2O9 the phosphor is around 55 nm. Thermoluminescence study was carried out for the phosphor with UV irradiation. The present phosphor can act as single host for red light emission in display devices. Vikas Dubey, Sadhana Agrawal, and Jagjeet Kaur Copyright © 2014 Vikas Dubey et al. All rights reserved. Hot Corrosion Behaviour of Detonation Gun Sprayed Al2O3-40TiO2 Coating on Nickel Based Superalloys at 900°C Tue, 11 Feb 2014 09:20:14 +0000 Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. These failures occur because of the usage of wide range of fuels such as, coal and oil at the elevated temperatures. Nickel based superalloys having excellent mechanical strength and creep resistance at elevated temperature are used under such environment but they lack resistance to hot corrosion at high temperature. To overcome these problems hot corrosion resistant coatings are deposited on these materials. In the current investigation Al2O3-40%TiO2 powder has been deposited on Superni 718 and AE 435 superalloys by Detonation Gun method. The hot corrosion performance of Al2O3-40%TiO2 coated as well as uncoated Superni 718 and AE 435 alloys has been evaluated in aggressive environment Na2SO4-82%Fe2(SO4)3 under cyclic conditions at an elevated temperature of 900°C. The kinetics of the corrosion is approximated by weight change measurements made after each cycle for total duration of 50 cycles. Scanning electron microscopy was used to characterize the hot corrosion products. The coated samples imparted better hot corrosion resistance than the uncoated ones. The AE 435 superalloy performed better than Superni 718 for hot corrosion in a given environment. N. K. Mishra, Naveen Kumar, and S. B. Mishra Copyright © 2014 N. K. Mishra et al. All rights reserved. Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization Analysis on Anticorrosive Activity of Thiophene-2-Carbaldehyde Derivative in Acid Medium Sun, 02 Feb 2014 06:45:25 +0000 The corrosion inhibition efficiency of thiophene-2-carbaldehyde tryptophan (T2CTRY) on mild steel (MS) in 1 M HCl solution has been investigated and compared using weight loss measurements, electrochemical impedance spectroscopy, and potentiodynamic polarization analysis. The Schiff base exhibited very good corrosion inhibition on mild steel in HCl medium and the inhibition efficiency increased with the increase in concentration of the inhibitor. The adsorption of the inhibitor on the surface of the corroding metal obeys Freundlich isotherm. Thermodynamic parameters (, Δ) were calculated using adsorption isotherm. Polarization studies revealed that T2CTRY acts as a mixed type inhibitor. A maximum of 96.2% inhibition efficiency was achieved by EIS studies at a concentration of 1 mM. Nimmy Kuriakose, Joby Thomas Kakkassery, Vinod P. Raphael, and Shaju K. Shanmughan Copyright © 2014 Nimmy Kuriakose et al. All rights reserved. Studies on Adsorption of DNA on Functional Ultrathin Films of Cationic Surfactant Sun, 12 Jan 2014 16:54:28 +0000 We have investigated the interaction of DNA with a highly ordered functional ultrathin layer of cationic surfactant, dioctadecyl ammonium bromide (DOAB). The ultrathin film of DOAB is fabricated by Langmuir-Blodgett technique onto the pretreated quartz crystal wafers. The solution of DNA in phosphate buffer saline (PBS) is injected through a flow cell in a quartz crystal microbalance (QCM) loaded with the functional ultrathin film. The QCM data indicate a slower kinetics (time constant  =  162.2 seconds) for the adsorption of DNA on DOAB layer as compared to PBS on DOAB. The surface morphology of the aggregation of DNA over the DOAB layer is investigated using atomic force microscope (AFM). The AFM image indicates the trapping of DNA over the DOAB layer. Such trapping of DNA can be potentially employed in the field of genomics. Monika Poonia, Anagh Pathak, V. Manjuladevi, and R. K. Gupta Copyright © 2014 Monika Poonia et al. All rights reserved. Comparison of the Strength of Binary Dislocation Junctions in fcc Crystals Thu, 09 Jan 2014 13:26:13 +0000 Discrete dislocation dynamics were used to determine the relative strengths of binary dislocation junctions in fcc crystals. Equilibrium junctions of different types Lomer, glissile, coplanar, and collinear were formed by allowing parallel dislocations of unequal length to react. The strengths were determined from the computed minimum strain rate versus the applied shear stress plots. The collinear configuration was found to be the strongest and coplanar the weakest. It was seen that the glissile junction could exist as two variants depending on which parent slip system the shear stress is applied. One variant of the glissile junction was found to be as strong as the collinear configuration. Naisheel Verdhan and Rajeev Kapoor Copyright © 2014 Naisheel Verdhan and Rajeev Kapoor. All rights reserved. Growth and Characterization of Agar Gel Grown Brushite Crystals Wed, 08 Jan 2014 11:49:04 +0000 Brushite [CaHPO4·2H2O] or calcium hydrogen phosphate dihydrate (CHPD) also known as urinary crystal is a stable form of calcium phosphate. The brushite crystals were grown by single and double diffusion techniques in agar-agar gel at room temperature. Effects of different growth parameters were discussed in single diffusion and double diffusion techniques. Good quality star, needle, platy, rectangular, and prismatic shaped crystals in single diffusion and nuclei with dendritic growth were obtained in double diffusion. These grown nuclei were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). SEM has shown the different morphologies of crystals; FTIR has confirmed the presence of functional groups; crystalline nature was supported by XRD, whereas the TGA indicates total 24.68% loss in weight and formation of stable calcium pyrophosphate (Ca2P2O7) at 500°C. V. B. Suryawanshi and R. T. Chaudhari Copyright © 2014 V. B. Suryawanshi and R. T. Chaudhari. All rights reserved. Influence of Rare Earth Doping on Microstructure and Luminescence Behaviour of Sodium Sulphate Mon, 06 Jan 2014 14:15:34 +0000 Na2SO4, Na2SO4: Li, and Na2SO4: Li, Eu, Dy phosphors were prepared by using slow evaporation technique followed by subsequent calcination at 400°C for 4 h. Doping with Li+ ion stabilized the thenardite phase of host matrix, while codoping with RE3+ stabilized the phase transformation from stable thenardite to metastable mirabilite crystal structure. The microstructure and morphology were studied by using scanning electron microscopy and transmission electron microscopy. The thermoluminescence studies revealed that isovalent doping of Li+ served as a quencher and addition of codopant introduces the additional trap sites in the host matrix. The room temperature emission spectra of Li-doped, RE3+-codoped, and undoped Na2SO4 were studied under ultraviolet radiation. For pure Na2SO4 the two peaks which appeared are at 364 and 702 nm, respectively. The emission intensities of RE3+-codoped samples increase with increase in dopant concentration. Y. S. Vidya and B. N. Lakshminarasappa Copyright © 2014 Y. S. Vidya and B. N. Lakshminarasappa. All rights reserved. Electrical Conductivity Studies of Polyaniline Nanotubes Doped with Different Sulfonic Acids Wed, 25 Dec 2013 13:34:18 +0000 Self-assembled polyaniline (PANI) nanotubes were prepared in the presence of three different sulfonic acids as dopant, namely, p-toluenesulfonic acid, camphorsulfonic acid, and tetrakis(4-sulfonatophenyl)porphyrin, by oxidative polymerization using ammonium peroxydisulfate as the oxidant. The morphology of the PANI nanotubes was determined by SEM and TEM and the electrical conductivity was measured as a function of temperature. The PANI nanotubes were also characterized by FTIR, XRD, UV-Vis, and cyclic voltammetry. We have found that the dopants had a noteworthy effect on the electrical conductivity whithout significant changes in the morphology of the PANI nanotubes. Mohd. Khalid, Milton A. Tumelero, Iuri. S. Brandt, Vinicius C. Zoldan, Jose J. S. Acuña, and Andre A. Pasa Copyright © 2013 Mohd. Khalid et al. All rights reserved. Fracture Toughness Reliability in Polycarbonate: Notch Sharpening Effects Sun, 22 Dec 2013 10:09:21 +0000 The effect of the notch sharpening on the fracture toughness obtained under linear elastic fracture mechanics has been analyzed in an amorphous polycarbonate. The samples for fracture characterization were sharpened via the traditional contact steel razor blade technique and the noncontact femtosecond laser ablation technique. The values of the fracture toughness of the specimens sharpened through femtosecond laser ablation were lower than those measured on samples sharpened using a steel razor blade. Moreover, the former was in plane strain state, but the latter did not verify the size criterion. The damage produced ahead of the crack tip through plastic deformation in the steel razor blade sharpened samples over the lack of damage in the femtolaser sharpened specimens explains the differences in the fracture toughness. It has been proven that there is a relationship between the plastic deformation at the crack front and the stress state. This has been assessed through the application of a fracture criterion for dissipative systems with small scale yielding. A. Salazar, J. Rodríguez, and A. B. Martínez Copyright © 2013 A. Salazar et al. All rights reserved. Enhancement of Mechanical and Thermal Properties of Polylactic Acid/Polycaprolactone Blends by Hydrophilic Nanoclay Wed, 18 Dec 2013 10:04:10 +0000 The effects of hydrophilic nanoclay, Nanomer PGV, on mechanical properties of Polylactic Acid (PLA)/Polycaprolactone (PCL) blends were investigated and compared with hydrophobic clay, Montmorillonite K10. The PLA/PCL/clay composites were prepared by melt intercalation technique and the composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). FTIR spectra indicated that formation of hydrogen bond between hydrophilic clay with the matrix. XRD results show that shifting of basal spacing when clay incorporated into polymer matrix. TEM micrographs reveal the formation of agglomerate in the composites. Based on mechanical properties results, addition of clay Nanomer PGV significantly enhances the flexibility of PLA/PCL blends about 136.26%. TGA showed that the presence of clay improve thermal stability of blends. DMA show the addition of clay increase storage modulus and the presence of clay Nanomer PGV slightly shift two of blends become closer suggest that the presence of clay slightly compatibilizer the PLA/PCL blends. SEM micrographs revealed that presence of Nanomer PGV in blends influence the miscibility of the blends. The PLA/PCL blends become more homogeneous and consist of single phase morphology. Chern Chiet Eng, Nor Azowa Ibrahim, Norhazlin Zainuddin, Hidayah Ariffin, Wan Md. Zin Wan Yunus, Yoon Yee Then, and Cher Chean Teh Copyright © 2013 Chern Chiet Eng et al. All rights reserved. Structure and Thermal Stability of Copper Nitride Thin Films Sun, 15 Dec 2013 14:27:21 +0000 Copper nitride (Cu3N) thin films were deposited on glass via DC reactive magnetron sputtering at various N2 flow rates and partial pressures with 150°C substrate temperature. X-ray diffraction and scanning electron microscopy were used to characterize the microstructure and morphology. The results show that the films are composed of Cu3N crystallites with anti-ReO3 structure. The microstructure and morphology of the Cu3N film strongly depend on the N2 flow rate and partial pressure. The cross-sectional micrograph of the film shows typical columnar, compact structure. The thermal stabilities of the films were investigated using vacuum annealing under different temperature. The results show that the introducing of argon in the sputtering process decreases the thermal stability of the films. Guangan Zhang, Zhibin Lu, Jibin Pu, Guizhi Wu, and Kaiyuan Wang Copyright © 2013 Guangan Zhang et al. All rights reserved. Crystal Growth and Characterization of a New NLO Material: p-Toluidine p-Toluenesulfonate Thu, 12 Dec 2013 18:33:47 +0000 Single crystals of p-Toluidine p-Toluenesulfonate (PTPT), an organic nonlinear optical (NLO) material, have been grown by slow evaporation method at room temperature using ethanol as solvent. The crystal system was confirmed from the single crystal X-ray diffraction analysis. The functional groups were identified using FTIR spectroscopy. UV-Vis-NIR spectrum showed that the UV cut-off wavelength of PTPT occurs at 295 nm and it has insignificant absorption in the wavelength region of 532–800 nm. The SHG efficiency of PTPT was measured by employing Kurtz and Perry powder technique using a Q-switched mode locked Nd: YAG laser emitting 1064 nm for the first time and it was found to be 52% of standard KDP. Thermal and mechanical properties of PTPT were examined by TG/DTA and Vickers microhardness test, respectively. M. Suresh, S. Asath Bahadur, and S. Athimoolam Copyright © 2013 M. Suresh et al. All rights reserved. Preparation and Characterization of HPMC/PVP Blend Films Plasticized with Sorbitol Thu, 12 Dec 2013 18:32:57 +0000 The aim of this present work is to investigate the effect of plasticizers like Sorbitol on microstructural and mechanical properties of hydroxypropyl methylcellulose (HPMC) and Polyvinylpyrrolidone (PVP) blend films. The pure blend and plasticized blend films were prepared by solution casting method and investigated using wide angle X-ray scattering (WAXS) method. WAXS analysis confirms that the plasticizers can enter into macromolecular blend structure and destroy the crystallinity of the films. FTIR spectra show that there are a shift and decrease in the intensity of the peaks confirming the interaction of plasticizer with the blend. Mechanical properties like tensile strength and Young’s Modulus decrease up to 0.6% of Sorbitol content in the films. Percentage of elongation at break increases suggesting that the plasticized films are more flexible than pure blend films. These films are suitable to be used as environmental friendly and biodegradable packaging films. H. Somashekarappa, Y. Prakash, K. Hemalatha, T. Demappa, and R. Somashekar Copyright © 2013 H. Somashekarappa et al. All rights reserved. Growth of Hierarchically Structured High-Surface Area Alumina on FeCrAl Alloy Wires Wed, 11 Dec 2013 10:00:58 +0000 The formation of metastable alumina phases due to the oxidation of commercial FeCrAl alloy wires (0.5 mm thickness) at various temperatures and time periods has been examined. Samples were isothermally oxidised in air using a thermogravimetric analyzer (TGA). The morphology of the oxidised samples was analyzed using an Electronic Scanning Electron Microscope (ESEM) and X-ray on the surface analysis was done using an Energy Dispersive X-Ray (EDX) analyzer. The technique of X-Ray Diffraction (XRD) was used to characterize the phase of the oxide growth. The entire study showed that it was possible to grow high-surface area gamma alumina on the FeCrAl alloy wire surfaces when isothermally oxidised above 800°C over several hours. Chandni Rallan, Aaron Akah, Patrick Hill, and Arthur Garforth Copyright © 2013 Chandni Rallan et al. All rights reserved. Effect of Steel Fibres and Low Calcium Fly Ash on Mechanical and Elastic Properties of Geopolymer Concrete Composites Tue, 10 Dec 2013 18:28:21 +0000 Effect of steel fibres and low calcium fly ash on mechanical and elastic properties of geopolymer concrete composites (GPCC) has been presented. The study analyses the impact of steel fibres and low calcium fly ash on the compressive, flexural, split-tensile, and bond strengths of hardened GPCC. Geopolymer concrete mixes were prepared using low calcium fly ash and activated by alkaline solutions (NaOH and Na2SiO3) with solution to fly ash ratio of 0.35. Crimped steel fibres having aspect ratio of 50 with volume fraction of 0.0% to 0.5% at an interval of 0.1% by mass of normal geopolymer concrete are used. The entire tests were carried out according to test procedures given by the Indian standards wherever applicable. The inclusion of steel fibre showed the excellent improvement in the mechanical properties of fly ash based geopolymer concrete. Elastic properties of geopolymer concrete composites are also determined by various methods available in the literature and compared with each other. Atteshamuddin S. Sayyad and Subhash V. Patankar Copyright © 2013 Atteshamuddin S. Sayyad and Subhash V. Patankar. All rights reserved. Physicochemical Studies on Thienyl Chalcone Derivative for Nonlinear Optical Application Thu, 05 Dec 2013 18:45:16 +0000 Single crystals of 1-(5-chlorothiophen-2-yl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (CTTMP) having nonlinear optical property have been grown by slow evaporation technique. The functional groups were identified by FT-IR and NMR techniques. The mechanical property of the crystals was studied using Vicker's microhardness tester and the load dependence hardness was observed. The material is dimensionally stable up to 112°C. The dielectric properties of the crystals were determined using semiconductor characterization system. The optical limiting behavior of the crystal was studied using Z-scan technique. A. N. Prabhu, A. Jayarama, K. Subrahmanya Bhat, K. B. Manjunatha, G. Umesh, and V. Upadhyaya Copyright © 2013 A. N. Prabhu et al. All rights reserved. Synthesis and Characterization of Lithium-Substituted Cu-Mn Ferrite Nanoparticles Thu, 28 Nov 2013 10:22:23 +0000 The effect of Li substitution on the structural and magnetic properties of LixCu0.12Mn0.88−2xFe2+xO4 (x = 0.00, 0.10, 0.20, 0.30, 0.40, and 0.44) ferrite nanoparticles prepared by combustion technique has been investigated. Structural and surface morphology have been studied by X-ray diffractometer (XRD) and high-resolution optical microscope, respectively. The observed particle size of various LixCu0.12Mn0.88−2xFe2+xO4 is found to be in the range of 9 nm to 30 nm. XRD result confirms single-phase spinel structure for each composition. The lattice constant increases with increasing Li content. The bulk density shows a decreasing trend with Li substitution. The real part of initial permeability () and the grain size (D) increase with increasing Li content. It has been observed that the higher the is, the lower the resonance frequency in LixCu0.12Mn0.88−2xFe2+xO4 ferrites is. M. A. Mohshin Quraishi and M. H. R. Khan Copyright © 2013 M. A. Mohshin Quraishi and M. H. R. Khan. All rights reserved.