Thermophysical performances of (Sm1-xLux)3TaO7 (x = 0, 0.1, 0.3 and 0.5) ceramics

To optimize thermophysical performances, Sm3TaO7 was doped with Lu3+ and pressureless sintered at 1600 ?C. It was shown that Sm3+ is partly substituted by Lu3+ cations and the (Sm1-xLux)3TaO7 ceramics with a single pyrochlore structure are obtained.With increasing x value from 0 to 0.5, the band gap increases gradually from 4.677 to 4.880 eV. Owing to the enhanced phonon scattering caused by Lu3+ doping, the thermal conductivities at 800 ?C of the prepared samples are in the range of 0.95-1.44W?K?1?m?1. It was also confirmed that the phase transition is restrained effectively by substituting Sm3+ with Lu3+. Due to the reduction of crystal lattice energy and average electro-negativity difference, the thermal expansion coefficient (TEC) is heightened with increasing Lu content. TEC achieves the highest value (10.45 ? 10?6 K?1 at 1200 ?C) at the equal molar ratio between Sm3+ and Lu3+ cations (i.e. x = 0.5), which is much higher than those of 7YSZ and Sm2Zr2O7 ceramics.

STUDY OF PHASES IN CRYSTALLINE SENTENCES

The objective of the study was to study the phases in the crystalline sentence of calcium molybdate with sodium metafanadat on the basis of phase equilibrium in binary sentence. For this sutyd, different mixtures are prepared based on different molar ratios and investigation is made about these different mixture physical properties. Finally, the study also draw a phase balanced chart for the studied substances. For methodology adopted, nine samples were prepared. The results shows that to form a solid solution as dissolving sodium metafandate in calcium molybdate up to 40% of sodium metafanadate and form a solid solution in this sentence confirms that the necessary conditions to form a soid solution. It is concluded that for difference less than 15%, unlimited solid solution is formed; whereas, for difference above 15%, limited solid solution is formed. Our conclusion also shows that these two elements solubility is limited where one possesses the characteristic of high electronegativity, while, the other possess the characteristic of low electro negativity.

Effect of Ge and Te on Physical Properties of Cu–Se–In–M (M = Ge, Te) Chalcogenide Glass

Cu5Se75In10M10 (M = Ge, Te) bulk chalcogenide glasses have been prepared by melt quench technique. XRD technique has been used for structural characterization. Absence of peaks confirms the amorphous nature of the studied composites. Some important physical parameters have been investigated theoretically i.e., average coordination number, constraints, density, molar volume, cohesive energy, electro negativity, heat of atomization, bond energy etc. Tichy-Ticha and Lankhorst approach has also been used to study the glass transition temperature Tg. Theoretical analysis of composition shows that there is significant change in the structure of the glass due to rigidity percolation.

Effect of hydration on the physical properties of glucose

The effect of hydration on the electronic properties of glucose (Gl) is studied by quantum mechanics by using DFT procedures atB3LYP/6-31g(d,p). Total dipole moment, the highest and the lowest occupied molecular orbital (HOMO/LUMO band gap energy) and molecular electrostatic potentials (ESPs) are calculated at the same level of theory for all model molecules. The results indicated that there is an enhancement in the electronic properties of Gl where TDM of Gl is increased from2.5454Debye to 4.3157Debye while HOMO/LUMO band gap energy is decreased from 13.0994 eV to 3.2749 eV. Also, the calculated ESP results are indicated that the electro-negativity is increased due to hydration which means that the reactivity is increased and hence the electronic properties are improved.

Molecular modeling analyses for polyvinylidene X (X=F, Cl, Br and I)

Polyvinylidene (PVDF) substituted with different halogens (F, Cl, Br and I) has been studied theoretically by performing some semiempirical calculations at PM3 to obtain some physical parameters and improve the electronic properties. As a result of substitution bond length increases from 1.1083 Ǻ to 1.9921 Ǻ; bond angels decreased from 105.5120° to95.3750°; total dipole moment is increased from 0.0013 to 9.8242 Debye and the energy gap is decreased from 14.2929 to 6.1591eV. In addition, ESP results are indicated that the electro-negativity of the studied model molecules is increased upon substitution. The change in these calculated physical parameters reflects the reactivity of PVD.

Surface Plasmon Resonance-Based Sensor Modeling

Exceptional optical and electrical characteristics of graphene based materials attract significant interest of the researchers to develop sensing center of surface Plasmon resonance (SPR) based sensors by graphene application. On the other hand refractive index calculation of graphene based structures is necessary for SPR sensor analysis. In this chapter first of all a new method for refractive index investigation of some graphene based structures are introduced and then the effect of carrier density variant in the form of conductance gradient on graphene based SPR sensor response is modeled. The molecular properties such as electro-negativity, molecular mass, effective group number and effective outer shell factor of the molecule are engaged. In addition each factor effect in the cumulative carrier variation is explored analytically. The refractive index shift equation based on these factors is defined and related coefficients are proposed. Finally a semi-empirical model for interpretation of changes in SPR curve is suggested and tested for some organic molecules.

Simulating surface tension of Sn-based lead free solder using an artificial neural network

Purpose Because of the complexity of relationship between surface tension and its decisive factors, such as temperature, concentration, electronic density, molar atomic volume and electro-negativity, a reasonable predicting model of surface tension of Sn-based solder alloys has not been developed yet. The paper aims to address the surface tension issue that has to be considered if the new lead free solder will be applied for electronics. Design/methodology/approach Using an artificial neural network (ANN) model with back-propagation (BP) algorithm, the surface tension for Sn-based binary solder alloys was simulated, and the comparison between the simulating results and data from experiments and literatures was analyzed as well. In addition, the relationship between surface tension and its decisive factors would be discussed based on the ANN and orthogonal design methods. Findings It is shown that the predicting model of surface tension of Sn-based solder alloys is constructed according to the BP–ANN theory, and the predicted value from the BP–ANN is in excellent agreement with the experimental results. The surface tension of Sn-based solders is determined by five factors, i.e. temperature, concentration, electronic density, molar atomic volume and electro-negativity. Among of the factors, molar atomic volume is major factor, and the order of degree of influence on surface tension is molar atomic volume > electro-negativity > electronic > density > concentration > temperature. Moreover, a simply reasonable equation is proposed to estimate the surface tension for Sn-based solders. Originality/value The five decisive factors of surface tension for Sn-based binary solder alloys have been analyzed theoretically, and a reasonable model of surface tension for Sn-based binary solder alloys is proposed as well. It is shown that ANN theory will be applied well to simulate the surface tension of Sn-based lead free solder.

Energy Harvesting Using Galvanically Synthesized Piezoelectric ZnO Nanorods on Flexible Polymer Film

This paper reports advancement in bringing flexible piezoelectric nanogenerators (NGs) closer to being realized in a commercial market. We have adopted a method to synthesize piezoelectric ZnO nanorods (NRs) on any electrically conductive surface without a seed layer or a specially selected substrate with matching lattice spacing. By contacting a metal with a dissimilar electro-negativity, a galvanic cell is created in the electrolyte growth medium. We have demonstrated the performance of the as grown NRs on a thin NG using common PET film. The device produced voltages in excess of three times higher than a parallel fabricated reference sample under bending loads.

Rapid Synthesis of Water-soluble NiCl2 Nanorods via Recrystallization for Super Capacitors Applications

Highly uniform NiCl2 nanorods were synthesized successfully via recrystallization and employed as electrode materials for super capacitors applications. The water-soluble Ni/NiCl2 electrode proves to show typical pseudocapacitive characteristics and delivers a very high specific capacitance of 1182.7 F g-1 at 2 A g-1. The charge storage and conversion process initiates from the chemically combination of Ni2+ and OH-, and maintains a reversible redox reaction of Ni(II) ↔ Ni(III) on the electrode. It opens a new insight into the fabrication of multifarious water-soluble inorganic salts for super capacitors applications using the ionic electro negativity parameter as the theoretical guideline.