Triethanolamine assisted sol-gel approach for obtaining two-dimensional magnesium aluminate nanosheets

Aqueous-phase synthetic route was applied for the preparation of magnesium aluminate spinel nanosheets with two-dimensional nanostructure through a sol-gel combustion approach, where triethanolamine was employed as a complexing agent and fuel. Results demonstrate that the as-synthesized two-dimensional nanosheets are well crystallized and show high purity. The pure magnesium aluminate nanoparticles with an average crystallite size of 25 nanometers were obtained at 1200 °C. Also, the two-dimensional magnesium aluminate powder contain nanosheets with thicknesses in the 20 nanometers–30 nanometers range, and the lateral size is in the range of ∼10 micrometers–30 micrometers.     

Fiber to the Home (FTTH) Automation Planning,Its Impact on Customer Satisfaction & Cost-Effectiveness

Wireless Personal Communications - The use of automated network planning systems is crucial for reducing the deployment cost and planning time of passive optical telecommunication networks....     

Directional characteristics of cylindrical radiators with an arc-shaped acoustic screen

Directional sound radiation by a cylinder surrounded with an arc-shaped (open circular) acoustic screen is examined. The corresponding boundary problem is solved with the partial domain technique. The method of asymptotic solutions was used to verify the conditions of solving this problem using the method of simple reduction. As a result of the analysis, the quantitative characteristics of the acoustic field of the cylindrical radiator inside the arc-shaped screen were evaluated.     

A Combo Smart Model of Blockchain with the Internet of Things (IoT) for the Transformation of Agriculture Sector

Wireless Personal Communications - Nowadays traditional techniques of living and earning are being transformed to modern smart technologies, taking their inspiration from the emerging trends....     

Nonreciprocal behaviour between photon and phonon in coupled optomechanical systems

It is shown that the asymmetry coupling between two coupled optomechanical cavities leads to special class of PT-symmetric model for optomechanical structure. Under these conditions, Hamiltonian is considered in blue and red sideband regime. In these cases, the asymmetric coupling between two cavities has been transferred such that the asymmetric beam-splitter or squeezing interaction is generated between optical and mechanical modes. Then, the amount of entanglement between the different optical and mechanical modes is calculated. The results define that PT-symmetry can improve the entanglement in special conditions. The proposed system provides good condition to investigate the nonreciprocal interaction between photon and phonon.     

The Effect of Geometric Parameters of Conical Cups on the Preform Shape in Two-Stage Superplastic Forming Process

A combination of sensitivity analysis and finite element simulation has been developed for the preform design in two-stage superplastic forming process. The aim is to present a simple approach to generate an estimate for the preform shape. In this respect, the commercial finite element software ABAQUS/Standard 6.8 was used as a computational tool and sensitivity analysis was used for preform design by minimizing the mean fractional deviation from the target thickness as an objective function. The predicted preform was verified through comparison with experimental results by investigating the deformation of AA5083 sheet at temperature of 500 °C. The effect of the geometric parameters of conical cups on the preform shape was examined. The results showed that the geometric parameters have a significant effect on the preform shape. By increasing the height and the cone angle of the final cup, the depth of the preform in the inner cavity decreases and the dome region is approached to the center of the preform cup. By increasing the corner radius of the final-die, only the height of the dome region decreases.     

Compact physical IR-drop models for chip/package co-design of gigascale integration (GSI)

The supply voltage decrease and power density increase of future GSI chips demand accurate models for the IR-drop. Compact physical IR-drop models of on-chip power/ground distribution networks are derived for two generic types of packages. In the early stages of design, these models enable accurate estimates of all required power/ground grid interconnect dimensions and chip pad counts that are needed for power distribution. The models also quantify the tradeoff between on-chip interconnect dimensions and the number of I/O pads required for power distribution and therefore enable rigorous chip/package co-design. Comparison with SPICE simulations show less than 1% and 5% error for the wire-bond package and the flip-chip package, respectively.     

Non-Linear Thermal Stability Analysis of SMA Wire-Embedded Hybrid Laminated Composite Timoshenko Beams on Non-Linear Hardening Elastic Foundation

In the present study, non-linear thermal post-buckling analysis of hybrid laminated composite Timoshenko beams embedded with the shape memory alloy (SMA) wires resting on a non-linear hardening elastic foundation were studied. Mechanical properties of composite media are considered temperature-dependent. The theory of Timoshenko beams and von Kármán's strain-displacement relations are applied simultaneously in virtual work principles to derive the system of non-linear equilibrium equations. Various types of boundary conditions such as clamped, simply supported, and rolled edges were studied for edge supports. Generalized Differential Quadrature Method (GDQM) was utilized to discrete the equilibrium equations in space domain. Different types of lay-ups, such as symmetric and asymmetric, were considered. Post-buckling paths are depicted for different values of non-linear elastic foundation parameters, volume fractions, pre-strains of the SMA fibers, and boundary conditions. The one-dimensional thermo-mechanical constitutive law suggested by Brinson [1 L. C. Brinson , One-Dimensional Constitutive Behavior of Shape Memory Alloys: Thermomechanical Derivation with Non-Constant Material Functions and Redefined Martensite Internal Variable , Journal of Intelligent Material Systems and Structures , vol. 4 , no. 2 , pp. 229 – 242 , 1993 .[Crossref] , [Google Scholar]] is applied to model the SMA wires. Numerical results make it possible to recognize that increases in the volume fraction and pre-strain of SMA lead to a dramatic enhancement in thermal buckling and post-buckling capacity of the beam. Pre-buckling, buckling, and post-buckling behavior of the beam are totally different and this is due to variations among critical buckling, austenite start and finish temperatures. Due to the recovery stress of SMA wires, particular consequences are shown.     

Effect of HPC-PANI/SIO2 Emulsion Nanocomposite in Poly(vinyl acetate) for Corrosion-Resistant Coatings

Emulsion nanoparticles of polyaniline were synthesized in an aqueous solution using ammonium persulfate as an oxidant in the presence of nanometer-size SiO₂ and hydroxylpropylcellulose as a stabilizer. Different concentrations of prepared nanocomposites were blended with poly(vinyl acetate) as the major matrix and coated on the carbon steel. The product was characterized and compared by (XRD), (FTIR), (SEM), and (TEM). According to the results 1 wt.% of HPC-PANI/SiO₂ nanocomposite in PVAc has a much lower corrosion current in NaCl solution and 3 wt.% of HPC-PANI/SiO₂ nanocomposite in PVAc has the best corrosion protection in HCl.