Diagnostics of Bolted Joints in Vibrating Screens Based on a Multi-Body Dynamical Model.

The condition-based maintenance of vibrating screens requires new methods of their elements' diagnostics due to severe disturbances in measured signals from vibrators and falling pieces of material. The bolted joints of the sieving deck, when failed, require a lot of time and workforce for repair. In this research, the authors proposed the model-based diagnostic method based on modal analysis of the 2-DOF system, which accounts for the interaction of the screen body and the upper deck under conditions of bolted joint degradation. It is shown that the second natural mode with an out-of-phase motion of the upper deck against the main screen housing may coincide with the excitation frequency or its higher harmonics, which appear when vibrators' bearings are in bad condition. This interaction speeds up bolt loosening and joint opening by the dynamical loading of higher amplitude. The proposed approach can be used to detune the system from resonance and anti-resonance to reduce maintenance costs and energy consumption. To prevent abrupt failures, such parameters as second natural mode frequency, damping factor, and phase space plot (PSP) distortion measures are proposed as bolt health indicators, and these are verified on the laboratory vibrating screen. Also, the robustness is tested by the impulsive non-Gaussian noise addition to the measurement data. A special diagram was proposed for the bolted joints' strength capacity assessment and maintenance actions planning (tightening, replacement), depending on clearance in the joints.

Electrochemical Pseudocapacitors Based on Ternary Nanocomposite of Conductive Polymer/Graphene/Metal Oxide: An Introduction and Review to it in Recent Studies.

This review gives an overview of the synthesis, surface and electrochemical investigations over ternary nanocomposite of conductive polymers in the development of new supercapacitors. They utilize both Faradaic and non-Faradaic procedures to store charge, leading to higher specific capacitance and energy density, higher cell voltage, longer life cycle and moderated power density. Owing to a unique combination of features such as superb electrical conductivity, corrosion resistance in aqueous electrolytes, highly modifiable nanostructures, long cycle life and the large theoretical specific-surface area, the use of ternary nanocomposites as a supercapacitor electrode material has become the focus of a significant amount of current scientific researches in the field of energy storage devices. In these nanocomposites, graphene not only can be utilized to provide a substrate for growing nanostructured polymers in a polymer-carbon nanocomposite structure in order to overcome the insulating nature of conductive polymers at dedoped states, but also is capable of providing a platform for the decoration of metal oxide nanoparticles to avoid their agglomeration. In this regard, synthesis, characterization and performance of different ternary nanocomposites of conductive polymer/graphene/metal oxide are discussed in detail. These remarkable results demonstrate the exciting commercial potential for high performance, environmentally friendly and low-cost electrical energy storage devices based on ternary nanocomposite of conductive polymer/graphene/metal oxide.

Electrochemical synthesis of Sm2O3 nanoparticles: Application in conductive polymer composite films for supercapacitors.

A novel electrosynthetic method was introduced to synthesize of Sm2O3 nanoparticles and furthermore, for improving the electrochemical performance of conductive polymer, hybrid POAP/Sm2O3 films have then been fabricated by POAP electropolymerization in the presence of Sm2O3 nanoparticles as active electrodes for electrochemical supercapacitors. The structure, morphology, chemical composition of Sm2O3 nanoparticles was examined. Surface and electrochemical analyses have been used for characterization of Sm2O3 and POAP/Sm2O3 composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. The supercapacity behavior of the composite film was attributed to the (i) high active surface area of the composite, (ii) charge transfer along the polymer chain due to the conjugation form of the polymer and finally (iii) synergism effect between conductive polymer and Sm2O3 nanoparticles.

Electrosynthesis of neodymium oxide nanorods and its nanocomposite with conjugated conductive polymer as a hybrid electrode material for highly capacitive pseudocapacitors.

Herein, we report for the first time a facile and cost-efficient synthesis of metal oxide nanostructures comprised of nanorods type without the use of any additive. Nd(OH)3 and Nd2O3 nanorods were obtained by ultrasound wave assisted pulse electrochemical deposition in a Nd(NO3)3·6H2O nitrate bath. In addition, the interconnected nanorods were mesoporous leading to large electrochemical active sites for the redox reaction and fast ion transport within the Nd2O3 nanorods. Furthermore, for improving the electrochemical performance of conductive polymer, hybrid POAP/Nd2O3 films have then been fabricated by POAP electropolymerization in the presence of Nd2O3 nanorods as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of Nd2O3 and POAP/Nd2O3 composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Prepared composite film exhibited a significantly high specific capacity, high rate capability and excellent cycling stability. Importantly, electrochemical investigation show that POAP/Nd2O3 nanorods composite material has better properties than POAP without Nd2O3 nanorods, suggesting it can be used as supercapacitor electrode material with excellent specific capacitance (379Fg-1) which indicates this material is a promising electrode material for energy storage applications in high-performance pseudocapacitors.

Pulse electrosynthesis of novel wormlike gadolinium oxide nanostructure and its nanocomposite with conjugated electroactive polymer as a hybrid and high efficient electrode material for energy storage device.

An effective approach for increasing the life cycle of pure p-type conductive polymers is combining conventional conductive polymers and nanomaterials to fabricate hybrid electrodes. In this paper, Gadolinium oxide (Gd2O3) has first been synthesized using pulse electrochemical approach. Hybrid POAP/Gd2O3 films have then been fabricated by POAP electropolymerization in the presence of Gd2O3 nanoparticles as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of Gd2O3 and POAP/Gd2O3 composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Specific capacitance, specific energy and specific power of the composite film are calculated 300F·g-1, 41.66Wh·kg-1 and 833.22W·kg-1 respectively. This work introduces new nanocomposite materials for electrochemical redox capacitors with such advantages as the ease of synthesis, high active surface area and stability in an aqueous electrolyte.

Novel electroactive nanocomposite of POAP for highly efficient energy storage and electrocatalyst: Electrosynthesis and electrochemical performance.

In this work, we presented facile route for fabrication of poly ortho aminophenol (POAP) POAP and POAP/ZnO nanocomposite on the surface of the working electrode. The fractal dimension of nanocomposite films in the presence of counter ions was investigated. Surface morphology of the composite film was studied by surface microscopy techniques (SEM). The presence of ZnO in the films was confirmed by EDS analysis. The results indicate that a strong interaction exist at the interface of POAP and nano-ZnO. Different electrochemical methods including galvanostatic charge discharge experiments and cyclic voltammetry have been applied to study the system performance. This work introduces new nanocomposite materials for electrochemical redox capacitors with such advantages as the ease of synthesis, high active surface area and stability in an aqueous electrolyte. Furthermore, comparison with a Ni-POAP the Ni-POAP/ZnO electrode shows a better catalytic performance for the electrocatalytic oxidation of methanol in alkaline solution. It is observed that the in the presence of ZnO nanoparticles current density of electro-oxidation of methanol is almost constant in 400 cycles due to the stability of electrocatalyst in this cycle number and indicating that methanol reacted with the surface and no poisoning effect on the surface was observed.

2D and 3D-QSAR analysis of pyrazole-thiazolinone derivatives as EGFR kinase inhibitors by CoMFA and CoMSIA.

Two and Three-dimensional quantitative structure-activity relationship (2D, 3D-QSAR) study was performed for some pyrazole-thiazolinone derivatives as EGFR kinase inhibitors using the CoMFA, CoMSIA and GA-MLR methods. The utilized data set was split into training and test set based on hierarchical clustering technique. From the five CoMSIA descriptors, electrostatic field presented the highest correlation with the activity. The statistical parameters for the CoMFA (r(2)=0.862, q(2)=0.644) and CoMSIA (r(2)=0.851, q(2)=0.740) were obtained for the training set with the common substructure-based alignment. The obtained parameters indicated the superiority of the CoMSIA model over the CoMFA model. A test set consisted of seven compounds was used to evaluate the proposed models. The results of contour maps which were presented by each method lead to some insights for increasing the inhibition activity of compounds. The 2D-QSAR model was built based on three descriptors selected by genetic algorithm and showed high predictive ability (R(2) train= 0.843, Q(2) LOO=0.787). Molecular docking study was also performed to understand the type interactions presented in binding site of the receptor and ligand. The developed models in parallel with molecular docking can be employed to design and derive novel compounds with the potent EGFR inhibitory activity.