Agglomeration Effects on Static Stability Analysis of Multi-Scale Hybrid Nanocomposite Plates

We propose a multiscale approach to study the influence of carbon nanotubes’ agglomeration on the stability of hybrid nanocomposite plates. The hybrid nanocomposite consists of both macro- and nano-scale reinforcing fibers dispersed in a polymer matrix. The equivalent material properties are calculated by coupling the Eshelby-Mori-Tanaka model with the rule of mixture accounting for effects of CNTs inside the generated clusters. Furthermore, an energy based approach is implemented to obtain the governing equations of the problem utilizing a refined higher-order plate theorem. Subsequently, the derived equations are solved by Galerkin’s analytical method to predict the critical buckling load. The influence of various boundary conditions is studied as well. After validation, a set of numerical examples are presented to explain how each variant can affect the plate’s natural frequency.     

Application of Geo-electrical Tomography in Coupled Hydro-mechanical–Chemical Investigations in Heap Leaching

Mine Water and the Environment - A shortcoming of the heap leaching process is its inherent limited metal recovery rate, due primarily to preferential pathways, which reduces the efficiency of the...     

Fuzzy modeling of the forced convection heat transfer from a V‐shaped plate exposed to an air slot jet

This paper focuses on the application of fuzzy logic (FL) to predict the forced convection heat transfer from V‐shaped plate internal surfaces exposed to an air impingement slot jet. The aim of the present paper is to consider the effects of the angle of a V‐shaped plate (Φ), slot‐to‐plate spacing ratio (Z/W), and Reynolds number (Re) variation on average heat transfer from the V‐shaped plate internal surfaces. The data used for developing the FL structure was obtained experimentally by a Mach‐Zehnder interferometer. The proposed FL was developed using MATLAB functions. It was observed that the average Nusselt number will be decreased with an increase in jet spacing and be increased with an increase in Reynolds number and angle of V‐shaped plate. Moreover, it is also shown that fuzzy logic is a powerful technique to use for predicting heat transfer due to its low error rate. The average error of the fuzzy predictions compared with experimental data was found to be 0.33% for this study. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21009     

Hard- and soft-modeling approaches for resolution of complex formation of Co2+ and Ni2+ with glycine

Principal component analysis (PCA) was used to obtain information about the number of components in the complex formation equilibria of Co(2+) and Ni(2+) with glycine (Gly). In order to obtain a clearer insight into these complex formation systems, multivariate curve resolution-alternating least squares (MCR-ALS) was used. Using MCR-ALS as a soft-modeling method, well-defined concentration and spectral profiles were obtained under unimodality, non-negativity, and closure constraints. Based on the obtained results, an equilibrium model was proposed and subsequently, a hard-modeling method was used to resolve the complex formation equilibria completely. Due to the presence of multiple equilibria, the resolution of such systems is very difficult. The Co-Gly system was best described by a model consisting of M(GlyH), M(Gly), M(Gly)(2), M(Gly)(2)H, and M(Gly)(3) (M = Co(2+)) with the overall stability constants determined to be 7.10 ± 0.011, 5.14 ± 0.006, 9.28 ± 0.009, 13.75 ± 0.016, and 11.10 ± 0.010, respectively. On the other hand, the system of Ni-Gly was best fitted by a model containing M(GlyH), M(Gly), M(Gly)(2), M(Gly)(3), and M(Gly)(2)(OH) (M = Ni(2+)) with overall stability constants of 10.95 ± 0.04, 6.41 ± 0.03, 11.31 ± 0.03, 15.39 ± 0.06, and 14.32 ± 0.02, respectively.     

Doxorubicin-loaded albumin nanoparticles: formulation and characterization

The purpose of the present study was to develop Doxorubicin (Dox) loaded albumin nanoparticles for regional drug release in solid tumours. Bovine serum albumin nanoparticles were prepared by coacervation method. The nanoparticles were characterized using various techniques: Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Dynamic Light Scattering (DLS) technique and Laser Doppler Electrophoresis (LDE) method. The entrapment of Dox in albumin nanoparticles also found out and in vitro release of drug was studied. The results show that the size of albumin nanoparticles increases from Z average of 67 nm to 98 and 106 nm for two different methods; A and B of drug loading, respectively. The SEM results confirm the spherical shape of nanoparticles which made at 4 degrees C. The results show that the size of nanoparticles decreases by decreasing temperature in their production process.     

The synergy between multi-wall carbon nanotubes and Vulcan XC72R in microporous layers

In this study, the effects of the addition of multi-wall carbon nanotubes (MWCNTs) into a microporous layer (MPL) containing Vulcan XC72R on the oxygen reduction reaction (ORR) were studied. We tested various percentages of MWCNTs and Vulcan XC72R in the MPLs of gas-diffusion electrodes (GDEs) with various Pt loadings in the catalyst layer. The performance of the ORR in the electrodes was studied with linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. The structures of the MPLs were investigated by using scanning electron microscopy (SEM), mercury porosimetry (MP), and gas permeability. In addition, the optimum polytetrafluoroethylene (PTFE) content of the MPL was determined. Our results indicate that the performances of the GDEs are optimal under the following conditions: (a) 60 wt% MWCNTs and 40 wt% Vulcan XC72R with a Pt loading of 0.115 mg/cm²; (b) 80 wt% MWCNTs and 20 wt% Vulcan XC72R with a Pt loading of 0.5 mg/cm²; and (c) 40 wt% MWCNTs and 60 wt% Vulcan XC72R with a Pt loading of 1 mg/cm².     

Paper-based laminates produced with kraft lignin-rich phenol–formaldehyde resoles meet requirements for outdoor usage

Suitability of lignin–phenol–formaldehyde (LPF) resoles was investigated for manufacturing paper-based high-pressure laminates. As lignin source, pine kraft lignin and spruce sodium lignosulfonate were compared, substituting 40 wt% of phenol by lignin in each case. The synthesized resins were characterized for their viscosity development, solid content, pH, free formaldehyde as well as free phenol content and B-time. Paper-based high-pressure laminates were manufactured using the two different resins. The laminates were exposed to different test climates and were compared for boiling water resistance, thickness swelling, bending properties and impact energy. The results indicate that pine kraft lignin performs superior to spruce sodium lignosulfonate for utilization in paper based laminates for outdoor usage due to a lower affinity of the pine kraft LPF laminates to water.     

Optimal planning of distributed generation with application of multi-objective algorithm including economic,environmental and technical issues with considering uncertainties

This paper proposes a stochastic multi-objective model for integration of distributed generations (DGs) in distribution networks. The proposed model determines the optimal location and size of DGs by optimising different objective functions dependently and simultaneously subject to the operating constraints. If proper sizes of DGs are located in suitable sites and are also managed properly they can improve integrity, reliability and efficiency of the system. Regarding the widespread impact of uncertainties, some strategies must be devised in order to incorporate them well into power system modelling and hence achieve the best possible strategy to be adopted which its characteristics keep closer to reality. The most important uncertainties in network planning are load forecasting and market price errors. The proposed scheme is solved using non-dominated sorting genetic algorithms II, allowing the distribution company (DisCo) to exercise his/her personal preferences. To validate the effectiveness of the proposed scheme, simulations are carried out on a 33-bus distribution network and finally the attained results are discussed.