http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Thu, 30 May 2013 17:48:04 +0000 http://www.hindawi.com/journals/jmat/2013/706513/ Nowadays, one of the major issues of the PEMFC concerns the durability. Historically, carbon has been used as a catalyst support in PEMFC; nevertheless, under the environmental conditions of the cell, the carbon is oxidized, leaving the catalyst unsupported. In order to increase the stability and durability of the catalyst in the PEMFC, a novel nanostructured metallic oxide support is proposed. In this work, TiO2 was doped with Nb to obtain a material that combines chemical stability, high surface area, and an adequate electronic conductivity in order to be a successful catalyst support candidate for long-term PEMFC applications. The TiO2-Nb nanostructured catalyst support was physically and electrochemically characterized. According to the results, the TiO2-Nb offers high surface area and good particle dispersion; also, the electrochemical activity and stability of the support were evaluated under high potential conditions, where the TiO2-Nb proved to be much more stable than carbon. Edgar Valenzuela, Victor Ramos-Sanchez, Alejandro Adolfo Lambert Arista, and Oumarou Savadogo Copyright © 2013 Edgar Valenzuela et al. All rights reserved. Wed, 22 May 2013 09:03:58 +0000 http://www.hindawi.com/journals/jmat/2013/548026/ This paper presents the continuous flow operation of membraneless sodium percarbonate fuel cell (MLSPCFC) using acid/alkaline bipolar electrolyte. In the acid/alkaline bipolar electrolyte, percarbonate works both as an oxidant as well as reductant. Sodium percarbonate affords hydrogen peroxide in aqueous medium. The cell converts the energy released by H2O2 decomposition with H+ and OH− ions into electricity and produces water and oxygen. At room temperature, the laminar flow based microfluidic membraneless fuel cell can reach a maximum power density of 28 mW/cm2 with the molar ratio of [Percarbonate]/[NaOH] = 1 as fuel and [Percarbonate]/[H2SO4] = 2 as oxidant. The paper reports for the first time the use of sodium percarbonate as the oxidant and reductant. The developed fuel cell emits no CO2 and features no proton exchange membrane, inexpensive catalysts, and simple planar structure, which enables high design flexibility and easy integration of the microscale fuel cell into actual microfluidic systems and portable power applications. M. Gowdhamamoorthi, A. Arun, S. Kiruthika, and B. Muthukumaran Copyright © 2013 M. Gowdhamamoorthi et al. All rights reserved. Tue, 14 May 2013 13:13:13 +0000 http://www.hindawi.com/journals/jmat/2013/478681/ The effect of different variables (precursor reagents, temperature, irradiation time, microwave radiation power, and additives addition) on the final morphology of nano-ZnO obtained through the microwave assisted technique has been investigated. The characterization of the samples has been carried out by field emission scanning electron microscopy (FE-SEM) in transmission mode, infrared (FTIR), UV-Vis spectroscopy, and powder X-ray diffraction (XRD). The results showed that all the above-mentioned variables influenced to some extent the shape and/or size of the synthetized nanoparticles. In particular, the addition of an anionic surfactant (sodium di-2-ethylhexyl-sulfosuccinate (AOT)) to the reaction mixture allowed the synthesis of smaller hexagonal prismatic particles (100 nm), which show a significant increase in UV absorption. Gastón P. Barreto, Graciela Morales, and Ma. Luisa López Quintanilla Copyright © 2013 Gastón P. Barreto et al. All rights reserved. Thu, 09 May 2013 11:40:35 +0000 http://www.hindawi.com/journals/jmat/2013/852859/ This paper reports on the study of direct current (DC) magnetron glow discharge plasma characteristics in a cylindrical magnetron system in argon-nitrogen. Presence of nitrogen gas makes the plasma environment reactive, and it results in significant changes of the plasma properties—number density, electron temperature, floating potential, and sheath thickness. Applied magnetic field is a parameter which is closely related to proper deposition of thin film. Cylindrical Langmuir probe and Emissive probe are used as diagnostics for the estimation of various plasma parameters indicated earlier. Controlled titanium nitride (TiN) thin film deposition on bell-metal at different argon-nitrogen gases ratio is another important study reported. Sankar Moni Borah Copyright © 2013 Sankar Moni Borah. All rights reserved. Wed, 08 May 2013 15:01:44 +0000 http://www.hindawi.com/journals/jmat/2013/985763/ High phosphorus Ni-P alloy was deposited on aluminium substrate using electroless deposition route. Using zincating bath, the surface was activated before deposition. Deposition time was varied from 15 minutes to 3 hours. Deposit was characterised using scanning electron microscope with energy dispersive spectroscope, X-ray diffraction, and microhardness tester. The corrosion resistance was measured using Tafel extrapolation route. The medium was aqueous 5% HNO3 solution. The analysis showed that the deposit consisted of nodules of submicron and micron scale. The predominant phase in the deposit was nickel along with phosphides of nickel. Compared to substrate material, deposit showed higher hardness. With increase in deposition time, the deposit showed more nobleness in 5% HNO3 solution and nobleness reached a limiting value in 1 hour deposition time. N. Sridhar and K. Udaya Bhat Copyright © 2013 N. Sridhar and K. Udaya Bhat. All rights reserved. Wed, 08 May 2013 09:17:17 +0000 http://www.hindawi.com/journals/jmat/2013/702946/ Piezoelectric materials have wide band gap and no inversion symmetry. Only the orthorhombic phase of lead metaniobate (PbNb2O6) can be ferroelectric and piezoelectric below Curie temperature, but not the rhombohedral phase. High temperature piezoelectric applications in current decades have revived international interest in orthorhombic PbNb2O6, synthesis of which in pure form is difficult and not well documented. Second problem is that its impedance spectroscopy (IS) data analysis is still incomplete. Present work attempts to fill up these two gaps. Presently found synthesis parameters yield purely orthorhombic PbNb2O6, as checked by X-ray Rietveld analysis and TEM. Present 20 Hz to 5.5 MHz IS from room temperature to 700°C shows its ferroelectric Curie temperature to be one of the highest reported, >574°C for 0.5 kHz and >580°C for 5.5 MHz. Dielectric characteristics and electrical properties (like capacitance, resistance and relaxation time of the equivalent CR circuit, AC and DC conductivities, and related activation energies), as derived here from a complete analysis of the IS data, are more extensive than what has yet been reported in the literature. All the properties show sharp changes across the Curie temperature. The temperature dependence of activation energies corresponding to AC and DC conductivities has been reexamined. Kriti Ranjan Sahu and Udayan De Copyright © 2013 Kriti Ranjan Sahu and Udayan De. All rights reserved. Sun, 28 Apr 2013 10:41:21 +0000 http://www.hindawi.com/journals/jmat/2013/892050/ Under compressive loads combined with friction, some materials undergo Tribological Surface Transformations (TSTs) on the surface of the loaded parts and in the immediately vicinity, which in the case of metals, are known as irreversible solid-solid phase transformations. During the solid-solid phase transformations occurring under mechanical loads, TRansformation Induced Plasticity (TRIP) processes are generated at much lower stress levels than those associated with the yield strength of the material in classical plasticity. In order to assess the effects of thermomechanical coupling in these TSTs, a one-dimensional modelling based on irreversible solid-solid phase transformations and classical plasticity is presented and discussed. Grégory Antoni Copyright © 2013 Grégory Antoni. All rights reserved. Tue, 23 Apr 2013 15:23:44 +0000 http://www.hindawi.com/journals/jmat/2013/683268/ Hydroxyapatite nanoparticles compounds were synthesized. Natural hydroxyapatite and a linear polysaccharide (1–3 linked   β-D galactopyranose and 1,4 linked 3,6 anhydro-α-L-galactopyranose) were used as a precursor in its formation. Our purpose was to produce nanoparticles in the presence of a linear polysaccharide with the use of a gelification method. The powder sample was evaluated by scanning tunneling microscope (STM), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction pattern (XRD), differential thermal analysis (DTA), infrared (IR) analysis, and thermal gravimetric analysis (TGA). According to the results, it was found that these nanoparticles can successfully be synthesized using a polysaccharide in a solution. On the other hand, the XRD peak intensity corresponds to hydroxyapatite structure in the range of temperature of 810°C. The influence of the polysaccharide on the evolution of the nanoparticles has been demonstrated. This observation opens up new routes for the fabrication of nanoparticles using polysaccharides network. The synthesized nanoparticles have diameters ranging from 10 nm to 11 nm approximately. The elaboration conditions such as pH and concentration were optimized in this solution. Humberto A. Monreal Romero, José Mora Ruacho, Carlos A. Martínez Pérez, and Perla E. García Casillas Copyright © 2013 Humberto A. Monreal Romero et al. All rights reserved. Sun, 21 Apr 2013 15:59:39 +0000 http://www.hindawi.com/journals/jmat/2013/716452/ The Mn-doped ZnS nanoparticles with Mn content of 0–15 mol% were synthesized by a hydrothermal method from the solutions Zn(CH3COO)2 0.1 M, Mn(CH3COO)2 0.01 M, and Na2S2O3 0.1 M at 220°C for 15 h. These nanoparticles presented the cubic structure with average particle size about 16 nm. The yellow-orange photoluminescence (PL) band at 586 nm was attributed to the radiation transition of the electrons in 3d5 unfilled shell of Mn2+ ions [4T1(4G)-6A1(6S)] in ZnS matrix. The photoluminescence excitation (PLE) spectra monitored at the yellow-orange band, the absorption spectra also showed the near band edge absorption of 336–349 nm and the characteristic absorption bands of Mn2+(3d5) ions at 392, 430, 463, 468, 492, and 530 nm. These bands should be attributed to the absorption transitions of 3d5 electrons from the ground state 6A1(6S) to the excited states 4E(4D), 4T2(4D), 4A1(4G)-4E(4G), 4T2(4G), and 4T1(4G) of Mn2+ ions. The intensity of PL band and absorption bands of Mn2+(3d5) ions also increased with the Mn content from 0.1 to 9 mol%, but their peak positions were almost unchanged. The PLE spectra showed clearly the energy level splitting of Mn2+ ions in ZnS crystal field and allowed for the calculation of the splitting width between the excited states 4A1(4G), 4E(4G) about of 229 cm−1 (28.6 meV), and the Racah parameters  cm−1,  cm−1, and the crystal field strength  cm−1. The PL spectra with different excitation wavelengths corresponding to absorption transition bands of the PLE spectra allow for the discussion of the indirect and direct excitation mechanisms of Mn2+(3d5) ions in the ZnS crystal. Bui Hong Van, Pham Van Ben, Tran Minh Thi, and Hoang Nam Nhat Copyright © 2013 Bui Hong Van et al. All rights reserved. Thu, 18 Apr 2013 11:16:56 +0000 http://www.hindawi.com/journals/jmat/2013/359514/ Yttrium phosphate and dysprosium doped yttrium phosphate were synthesized from aqueous solutions using rare earth chloride, phosphoric acid, and traces of ammonium hydroxide. The synthesized material was then characterized for their structural investigations using powder X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) supplemented with energy dispersive X-ray analysis (EDAX). The spectroscopic investigations were carried out using Fourier transform infrared (FTIR) spectroscopy. The thermal stability was studied using differential thermogravimetric analysis (DTA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. X-ray diffraction analysis reveals that both yttrium phosphate and dysprosium doped yttrium phosphate belong to tetragonal system with lattice parameter  Å,  Å and  Å,  Å, respectively. The stoichiometry of the grown composition was established by energy dispersive X-ray analysis. The EDAX analysis suggests the presence of water molecules. The presence of water molecules along with orthophosphate group and metallic ion group was confirmed by FTIR analysis. Thermogravimetric analysis suggests that decomposition in case of yttrium phosphate takes place in three different stages and the final product stabilizes after 706°C, whereas in case of dysprosium doped yttrium phosphate the decomposition occurs in two different stages, and the final product stabilizes after 519°C. K. K. Bamzai, Nidhi Kachroo, Vishal Singh, and Seema Verma Copyright © 2013 K. K. Bamzai et al. All rights reserved. Wed, 17 Apr 2013 14:12:12 +0000 http://www.hindawi.com/journals/jmat/2013/515846/ We focus on the production of TiO2 nanofibers with controllable diameters using a facile electrospinning technique at room temperature. The resulting nanofibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible spectroscopy (UV-Vis). The most important electrospinning parameters including potential difference (kV), flow rate (mL/h), and the separation distance between electrodes (cm) were found to have significant influence on the diameter of the produced nanofibers. The photocatalytic performance of TiO2 nanofibers was successfully demonstrated for decolorization of Rhodamine B (Rh.B) under UV light irradiation. It was found that fiber diameter has a crucial influence on the photocatalytic performance of TiO2 nanofibers. Ali Akbar Ashkarran, Sima Eshghi, and Mohammad Reza Nourani Copyright © 2013 Ali Akbar Ashkarran et al. All rights reserved. Mon, 15 Apr 2013 10:42:02 +0000 http://www.hindawi.com/journals/jmat/2013/150671/ The present piece of work describes the industrial wastes and low grade ores (fly ash + quartz + ilmenite, as the coating material), deposited on mild steel substrates. In many cases it is found that porosity is an important factor on the coating surface. Knowledge about the extent of these porosity imperfections is critical since they influence a wide range of spray coated properties and behaviors. To decrease the porosity by optimizing necessary operating parameters, artificial neural network (ANN) technique is used. The aim of this investigation is to find out appropriate input vectors in ANN model. ANN experimental results indicate that the projection network has good generalization capability to optimize the porosity. Ajit Behera, S. C. Mishra, Asit Behera, and J. P. Dhal Copyright © 2013 Ajit Behera et al. All rights reserved. Wed, 10 Apr 2013 11:46:45 +0000 http://www.hindawi.com/journals/jmat/2013/206952/ Selective utilisation of unique properties of Salix viminalis wood enables preparation of materials of nanotechnologic properties. Thermal decomposition of lignin-cellulose organic matter results in the formation of a nanostructured porous carbon matrix (charcoal). Narrowed pore size distribution (PSD) in the subnanometer range allows to consider the charcoals as carbon molecular sieves (CMSs), which are capable of separating even chemically inert gases like neon, krypton, and nitrogen. High tolerance of Salix viminalis to heavy metal ions enables enriching living plant tissues with metal ions like lanthanum and manganese. Such ions may later form LaMnO3 with parallel transformation of plant tissues (organic matter) to carbon matrix using a heat treatment. In this way, one gets a hybrid material: a porous carbon matrix with uniformly suspended nanocrystallites of LaMoO3. The crystallites are in the catalytically active phase during the conversion of n-butanol to heptanone-4 with high yield and selectivity. Aleksandra W. Cyganiuk, Roman Klimkiewicz, Andrzej Olejniczak, Anna Kucińska, and Jerzy P. Łukaszewicz Copyright © 2013 Aleksandra W. Cyganiuk et al. All rights reserved. Wed, 10 Apr 2013 10:35:31 +0000 http://www.hindawi.com/journals/jmat/2013/297123/ A correlation between physicochemical characteristics of flocculants obtained by electron beam irradiation and their efficiency for wastewater treatment is presented. For real wastewater treatment, our interest was focused upon total suspended solids, fatty matter, and chemical oxygen demand. Flocculation studies were carried out using a standard jar test. A treatment option based on poly(acrylamide-co-acrylic acid) for wastewater taken from a slaughterhouse plant is presented. Gabriela Craciun, Elena Manaila, and Maria-Daniela Stelescu Copyright © 2013 Gabriela Craciun et al. All rights reserved. Tue, 09 Apr 2013 12:02:48 +0000 http://www.hindawi.com/journals/jmat/2013/614507/ Stable lyotropic chiral nematic liquid crystals (N*-LCs) of cellulose nanocrystals (CNs) were prepared via hydrolysis using sulfuric acid. The lyotropic N*-LCs were used as an asymmetric reaction field to synthesize polyaniline (PANI) onto CNs by in situ polymerization. As a primary step, we examined the mesophase transition of the N*-LCs of CNs suspension before and after in situ polymerization of aniline (ANI) by polarizing optical microscopy. The structure of nanocomposites of PANI/CNs was investigated at a microscopic level using Fourier transform infrared spectroscopy and X-ray diffraction. Influence of the CNs-to-ANI ratio on the morphology of the nanocomposites was also investigated at macroscopic level by scanning electron and transmission electron microscopies. It is found that the weight ratio of CNs to aniline in the suspension significantly influenced the size of the PANI particles and interaction between CNs and PANI. Moreover, electrical properties of the obtained PANI/CNs films were studied using standard four-probe technique. It is expected that the lyotropic N*-LCs of CNs might be available for an asymmetric reaction field to produce novel composites of conjugated materials. Dawei Zhang, Lihong Zhang, Bingzhe Wang, and Guangzhe Piao Copyright © 2013 Dawei Zhang et al. All rights reserved. Tue, 09 Apr 2013 12:00:45 +0000 http://www.hindawi.com/journals/jmat/2013/393017/ The powder synthesis of barium zirconate titanate (BZT) (BaZrTiO3) from the mechanochemical activation of BaCO3, ZrO2, and TiO2 was studied. The grinding effect, by using a planetary ball milling, on the crystallization temperature of BZT powders was analyzed. X-ray diffractometry, differential thermal analysis, thermogravimetric analysis, and scanning electronic microscopy (SEM) were used as characterization methods. The crystallization behavior of powders activated by high-energy grinding and the effect of grinding time on the BZT crystallization were analyzed. After grinding by 4 h, the BaZr(0.05)Ti(0.95)O3 sample was almost fully crystallized at . The results of dielectric and ferroelectric properties show that high-energy ball milling is a practical and promising way to prepare BZT ceramics. A. Frattini, A. Di Loreto, and O. De Sanctis Copyright © 2013 A. Frattini et al. All rights reserved. Mon, 08 Apr 2013 09:19:04 +0000 http://www.hindawi.com/journals/jmat/2013/703587/ Polycrystalline samples of Ni53.6Mn27.1Ga19.3 and Ni54.2Mn29.4Ga16.4 shape memory alloys were investigated using dilatometry. The longitudinal axes of the samples were perpendicular to the columnar grains. Both alloys showed positive shape memory effects. The martensitic phase transformation occurred without hysteresis in both alloys with transformation temperatures of 174°C for the Ni53.6Mn27.1Ga19.3 alloy and 253°C for the Ni54.2Mn29.4Ga16.4 alloy. The dilatation characteristics for both alloys were determined in three perpendicular directions. The strain associated with the internal stress at the interface between the two martensitic structures and the two grains affected the dilatation characteristics in the y and z directions (perpendicular to the longitudinal axis of the sample). The microstructure was determined for all the directions investigated. To investigate the mechanical history, a round cross-section of the Ni54.2Mn29.4Ga16.4 sample was machined using a milling machine along the longitudinal axis so that both sides of the sample were symmetrical. This sample treatment changed the dilatation characteristics of the martensite and austenite. The study and analysis of the dilatation characteristics of the thermal cycle showed the relaxation of internal stresses and the reorientation of the martensitic variants. Alexandra Rudajevova and Jiří Pospíšil Copyright © 2013 Alexandra Rudajevova and Jiří Pospíšil. All rights reserved. Mon, 08 Apr 2013 09:01:26 +0000 http://www.hindawi.com/journals/jmat/2013/987328/ Frequency-dependent electric and dielectric properties of the porous Sm0.5Sr0.5CoO3−δ cathode prepared through conventional combustion synthesis technique were studied in the temperature range 298 K–973 K. The crystal symmetry, space group, and unit cell dimensions were confirmed by analyzing XRD pattern. XRD analysis indicates the formation of a single-phase orthorhombic structure with space group Pnma 62. Scanning electron microscopy technique was used to examine the morphology of the sample. Scanning electron microscopy study showed the formation of porous structure with an average grain size about 850 nm. From the electrical study, it is observed that the conduction in Sm0.5Sr0.5CoO3−δ sample takes place through the hopping mechanism and follows the inverse universal power law. The correlated barrier hopping model was employed successfully to explain the mechanism of charge transport in Sm0.5Sr0.5CoO3−δ. Further, the ac conductivity data was used to evaluate the minimum hopping length and apparent activation energy. The minimum hopping length was found to be ~10−4 times smaller than the grain size of Sm0.5Sr0.5CoO3−δ. The peaking behaviour of the real part of dielectric constant with frequency was explained using the Rezlescu model. This study helps to confirm that the charge transportation in Sm0.5Sr0.5CoO3−δ is due to two types of charge carriers. S. S. Pawar, K. P. Shinde, A. G. Bhosale, and S. H. Pawar Copyright © 2013 S. S. Pawar et al. All rights reserved. Mon, 08 Apr 2013 08:07:41 +0000 http://www.hindawi.com/journals/jmat/2013/352578/ Hardness and strength values of over 55 copper alloys strengthened by solid solution strengthening, precipitation hardening, cold working, and dispersion strengthening were compiled. The yield strength (YS) and ultimate tensile strength (UTS) values of the copper alloys examined ranged between 50 to 1300 MPa and 200 to 1400 MPa, respectively. The compiled values were classified based on strain-hardening potential an indirect method to understand the effect of strain-hardening characteristics. Least squares regression analysis was employed to establish correlations between strength and Vickers hardness values. Strain-hardening potential showed a significant effect on the correlations. In all the cases, a linear relation was obtained for both YS and UTS with hardness for the entire range of values under analysis. Simple empirical equations were proposed to estimate the strength using bulk hardness. The proposed correlations obtained for the entire range of values were verified with experimental values. A good agreement was observed between experimental and predicted values. S. Chenna Krishna, Narendra Kumar Gangwar, Abhay K. Jha, and Bhanu Pant Copyright © 2013 S. Chenna Krishna et al. All rights reserved. Thu, 04 Apr 2013 16:04:58 +0000 http://www.hindawi.com/journals/jmat/2013/413578/ Blends of polyvinyl alcohol (PVA) and angico gum (AG) and/or cashew gum (CG) were used to produce films by casting method. Morphological and mechanical properties of these films were studied and compared to the properties of a commercial collagen membrane of bovine origin (MBO). The films presented thickness varying from 70 to 140 μm (PVA/AG) and 140 to 200 μm (PVA/CG). Macroscopic analysis showed that a PVA/CG film was very similar to MBO regarding the color and transparency. The higher values of tensile strength (TS) and elastic modulus (EM) were observed in the film. On the other hand, PVA/CG and PVA/CG-AG presented the highest value of percentage of elongation (E%). Pearson’s Correlation Analysis revealed a positive correlation between TS and EM and a negative correlation between E% and EM. The PVA/CG film presented mechanical properties very similar to MBO, with the advantage of a higher E% (11.96) than MBO (2.94). The properties of the PVA blended films depended on the polysaccharide added in the blend, as well as the acid used as a catalyst. However, all produced films presented interesting mechanical characteristics which enables several biotechnological applications. Fábio E. F. Silva, Maria Carolina B. Di-Medeiros, Karla A. Batista, and Kátia F. Fernandes Copyright © 2013 Fábio E. F. Silva et al. All rights reserved. Sun, 31 Mar 2013 14:32:24 +0000 http://www.hindawi.com/journals/jmat/2013/216732/ Single crystals of pure and ammonium chloride-doped urea L-malic acid (ULMA) were grown by slow evaporation technique. Many interesting results on several properties of ammonium chloride impurity added to ULMA single crystals have been observed and studied. The different morphology of ammonium chloride-doped ULMA crystals was noticed and the effect of ammonium chloride doping on the growth, optical, and hardness properties has been investigated. The presence of functional groups has been estimated by FTIR analysis. The lattice parameters of the grown crystals were studied by single crystal X-ray diffraction technique. Powder X-ray diffraction studies confirm the diffraction planes of the grown crystals. The UV-visible spectrum shows the cutoff wavelength at 220 nm. A study on the thermal properties has also been carried out. The NLO property of the grown crystals was confirmed by SHG studies. B. Sivasankari and P. Selvarajan Copyright © 2013 B. Sivasankari and P. Selvarajan. All rights reserved. Sat, 30 Mar 2013 14:36:03 +0000 http://www.hindawi.com/journals/jmat/2013/676920/ Described here is fabrication of a pH-sensitive, optically transparent transducer composed of a planar indium-tin oxide (ITO) electrode overcoated with a poly(aniline) (PANI) thin film and a porous sol-gel layer. Adsorption of the PANI film renders the ITO electrode sensitive to pH, whereas the sol-gel spin-coated layer makes the upper surface compatible with fusion of phospholipid vesicles to form a planar supported lipid bilayer (PSLB). The response to changes in the pH of the buffer contacting the sol-gel/PANI/ITO electrode is pseudo-Nernstian with a slope of 52 mV/pH over a pH range of 4–9. Vesicle fusion forms a laterally continuous PSLB on the upper sol-gel surface that is fluid with a lateral lipid diffusion coefficient of 2.2 μm2/s measured by fluorescence recovery after photobleaching. Due to its lateral continuity and lack of defects, the PSLB blocks the pH response of the underlying electrode to changes in the pH of the overlying buffer. This architecture is simpler to fabricate than previously reported ITO electrodes derivatized for PSLB formation and should be useful for optical monitoring of proton transport across supported membranes derivatized with ionophores and ion channels. Ahmed Al-Obeidi, Chenhao Ge, Kristina S. Orosz, and S. Scott Saavedra Copyright © 2013 Ahmed Al-Obeidi et al. All rights reserved. Thu, 28 Mar 2013 14:16:44 +0000 http://www.hindawi.com/journals/jmat/2013/539312/ 2-Amino-4,6-dimethylpyrimidinium p-hydroxybenzoate (ADPHB), a novel organic material, was synthesized, and crystals were grown by slow evaporation solution growth method. The cell parameters and crystalline perfection of the grown crystal were studied by single crystal and powder X-ray diffraction analyses. The presence of various functional groups of the grown crystal was confirmed using Fourier Transform infrared spectral analysis. UV-Visible spectrum shows that ADPHB crystals have high transmittance in the range 305–900 nm. The refractive index and transient photoluminescence properties of the grown crystal were analyzed. The laser induced surface damage threshold, optical birefringence, and second harmonic generation efficiency of the grown crystal were studied. S. Sudhahar, M. Krishna Kumar, A. Silambarasan, R. Muralidharan, and R. Mohan Kumar Copyright © 2013 S. Sudhahar et al. All rights reserved. Thu, 28 Mar 2013 11:54:20 +0000 http://www.hindawi.com/journals/jmat/2013/809205/ Elastic-plastic stresses, strains, and displacements have been obtained for a thin rotating annular disk with exponentially variable thickness and exponentially variable density with nonlinear strain hardening material by finite difference method using Von-Mises' yield criterion. Results have been computed numerically and depicted graphically. From the numerical results, it can be concluded that disk whose thickness decreases radially and density increases radially is on the safer side of design as compared to the disk with exponentially varying thickness and exponentially varying density as well as to flat disk. Sanjeev Sharma and Yadav Sanehlata Copyright © 2013 Sanjeev Sharma and Yadav Sanehlata. All rights reserved. Tue, 26 Mar 2013 11:19:50 +0000 http://www.hindawi.com/journals/jmat/2013/718525/ A model and its numerical implementation are presented which describe the formation of mixed Zn/ZnO droplets by rapid cooling of a mixture of zinc vapor and oxygen. The model incorporates a nucleation step producing pure metal droplets of a fixed size and three condensation-like processes determining the further growth of the droplets by adding metal atoms and oxygen. Properties to characterize the resulting droplet population are obtained from the model. Examples such as the number density of particles, their average chemical composition and surface area, or the particle mass distribution are presented. The model is verified on a qualitative level by comparing with experimental data the influence of the quench rate and the initial partial pressures of the reactants on the average chemical composition of the product. The model predicts, conforming qualitatively with experimental findings, that increasing the quench rate has little influence on the chemical composition of the products but that decreasing the initial partial pressures of zinc results in less oxidized products, thus, a higher average zinc content. Ivo Alxneit and Hans Rudolf Tschudi Copyright © 2013 Ivo Alxneit and Hans Rudolf Tschudi. All rights reserved. Mon, 25 Mar 2013 11:00:24 +0000 http://www.hindawi.com/journals/jmat/2013/613092/ Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were analyzed by FT-IR spectroscopy. Using Vickers microhardness tester, mechanical strength of the material was found. Dielectric studies of pure and doped LAT single crystals were carried out. The doped LAT crystal is found to have efficiency higher than that of pure LAT crystal. K. Rajesh, B. Milton Boaz, and P. Praveen Kumar Copyright © 2013 K. Rajesh et al. All rights reserved. Mon, 25 Mar 2013 10:10:47 +0000 http://www.hindawi.com/journals/jmat/2013/260982/ An electrical conduction versus temperature model using a Hall device was developed. In the case of InAs, InGaAs, and GaAs MBE epilayers, the prediction agrees well with the experimental results. Herein, we explain here how these calculated fractions of total conductivity describe the measured values. The method allows for the calculation of the carrier concentration and mobility of each component of a multicarrier system. The extracted concentrations are used to characterise the different components of charge transport in the active layer. The conductance values G [S] of these components of charge transport were obtained. Also the scattering events for the investigated samples are presented. The analysis of the experimental results for three semiconductor compositions and different concentrations demonstrates the utility of our method in comparing the conductance of each component of the multilayered system as a function of temperature. Andrzej Wolkenberg Copyright © 2013 Andrzej Wolkenberg. All rights reserved. Thu, 21 Mar 2013 14:17:02 +0000 http://www.hindawi.com/journals/jmat/2013/897343/ Complex formation and liquid-liquid extraction were studied in a system containing cobalt(II), 4-(2-pyridylazo)resorcinol (PAR), 1,4-diphenyl-3-(phenylamino)-1H-1,2,4-triazole (Nitron, Nt), water, and chloroform. The effect of some experimental parameters (pH, shaking time, concentration of PAR, and concentration of Nt) was systematically investigated, and the optimum conditions for cobalt extraction as an ion-association complex, (NtH+)[Co3+(PAR)2], were found. The following key equilibrium constants were calculated: constant of association , constant of distribution , and constant of extraction . Beer’s law was obeyed for Co concentrations up to 1.7 μg mL−1 with a molar absorptivity of L mol−1 cm−1 at  nm. Some additional characteristics, such as limit of detection, limit of quantification, and Sandell’s sensitivity, were estimated as well. Petya Vassileva Racheva, Kiril Blazhev Gavazov, Vanya Dimitrova Lekova, and Atanas Nikolov Dimitrov Copyright © 2013 Petya Vassileva Racheva et al. All rights reserved. Wed, 20 Mar 2013 16:18:53 +0000 http://www.hindawi.com/journals/jmat/2013/696428/ This paper deals with the laboratory investigation of cathode-ray-tube- (CRT-) glass-based glass foam, the so-called “Geofil-Bubbles” which can be applied in many fields, mainly in the construction industry (lightweight concrete aggregate, thermal and sound insulation, etc.). In this study, the main process engineering material properties of raw materials, such as particle size distribution, moisture content, density, and specific surface area, are shown. Then, the preparation of raw cathode ray tube glass waste is presented including the following steps: crushing, grinding, mixing, heat curing, coating, and sintering. Experiments were carried out to optimize process circumstances. Effects of sintering conditions—such as temperature, residence time, and particle size fraction of green pellet—on the mechanical stability and particle density of glass foam particles were investigated. The mechanical stability (abrasion resistance) was tested by abrasion test in a Deval drum. Furthermore, the cell structure was examined with optical microscopy and SEM. We found that it was possible to produce foam glass (with proper mechanical stability and particle density) from CRT glass. The material characteristics of the final product strongly depend on the sintering conditions. Optimum conditions were determined: particle size fraction was found to be 4–6 mm, temperature 800°C, and residence time 7.5 min. G. Mucsi, B. Csőke, M. Kertész, and L. Hoffmann Copyright © 2013 G. Mucsi et al. All rights reserved. Tue, 19 Mar 2013 16:16:38 +0000 http://www.hindawi.com/journals/jmat/2013/630156/ Mechanical and tribological properties of the thin carbon film with tungsten interlayer were investigated. The carbon film (130 nm) and the tungsten interlayer (20 nm) were prepared by ion beam assisted deposition (IBAD) method. Both layers were electron beam evaporated and were simultaneously irradiated by the beam of argon (Ar) or nitrogen (N) ions with energy of 700 eV. Mechanical properties of the thin carbon film with tungsten interlayer were investigated by the nanoindentation method. Concerning tribological properties the coefficient of friction was investigated by means of pin on disc tribometer. Phase composition was investigated by X-ray diffraction method (XRD), and bonding characterization of carbon thin film was characterized by Raman spectroscopy. Petr Vlcak, Frantisek Cerny, Zdenek Tolde, Josef Sepitka, Ivan Gregora, and Stanislav Danis Copyright © 2013 Petr Vlcak et al. 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