Thermally reused solar energy harvesting using current mirror cells

This paper implements a simultaneous solar and thermal energy harvesting system, as a hybrid energy harvesting (HEH) system, to convert ambient light into electrical energy through photovoltaic (PV) cells and heat absorbed in the body of PV cells. Indeed, a solar panel equipped with serially connected thermoelectric generators not only converts the incoming light into electricity but also takes advantage of heat emanating from the light. In a conventional HEH system, the diode block is used to provide the path for the input source with the highest value. In this scheme, at each time, only one source can be handled to generate its output, while other sources are blocked. To handle this challenge of combining resources in HEH systems, this paper proposes a method for collecting all incoming energies and conveying its summation to the load via the current mirror cells in an approach similar to the maximum power point tracking. This technique is implemented using off-the-shelf components. The measurement results show that the proposed method is a realistic approach for supplying electrical energy to wireless sensor nodes and low-power electronics.     

Difference in subsurface damage in indented specimens with and without bonding layer

This paper aims to assess the applicability of the bonded–interface technique (BIT) that has been used for examining sub-surface damage in brittle materials. With the aid of the finite element method, the indentation stress fields in alumina specimens with and without a bonded–interface were analysed. It was found that the bonded–interface greatly alters the stress distribution in the neighbourhood of the interface. The high-stress zone shifts away from the interface, and extends to the surface. Both glue layer mechanical properties and bond thickness play a limited role in the overall stress field of the BIT alumina. Comparisons of theoretical predictions with experimental observations showed that, to a great extent, the BIT presents a different pattern of sub-surface damage. The study clarifies the applicability of the BIT and offers a useful guideline for practitioners.     

Influence of substrate rotation speed on the nanostructure of sculptured Cu thin films

Different rotation speeds of the substrate about its surface normal were used to produce sculptured copper thin films of ∼ 90 nm thickness. X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) were employed to obtain nano-structure and morphology of these films. Their optical properties were measured by spectrophotometry in the spectral range of 340-850 nm. Real and imaginary refractive indices, film thickness and fraction of metal inclusion in the film structure were obtained from optical fitting of the spectrophotometer data.     

Wrinkling of sandwich column: comparison between finite element analysis and analytical solutions

Wrinkling analysis of sandwich columns was carried out. Two methods were used, namely finite element methods and analytical solutions. In the finite element methods, shell elements based on Reissner–Mindlin were employed across the beam thickness. A very fine element was used to model both the skin and the core across the beam thickness. The buckling mode was increased up to 100 in order to be able to model the wrinkling mode. The analytical solutions used energy methods and Raleigh–Ritz solutions developed earlier by the author. Finally, comparisons were made with experimental data taken from published results. Good agreements were achieved between the experimental results and both the finite element and analytical solution. The difference was less than 10%. Both finite element and analytical solutions were able to predict both symmetrical and asymmetrical wrinkling.     

Combined Computational and Experimental Study on the Adsorption and Inhibition Effects of N2O2 Schiff Base on the Corrosion of API 5L Grade B Steel in 1 mol/L HCI

The electrochemical behavior of low carbon steel （API 5L grade B） in 1 mol/L HCI solution with different concentrations of N,Nr-bis（4-formylphenol）-trimethylenediamine Schiff base was studied by electrochemical techniques and density functional theory analysis. The inhibition efficiency was found to increase with increasing inhibitor concentration and decreased with increasing temperature. The high inhibition efficiency was attributed to the blocking of active sites by adsorption of inhibitor molecules on the steel surface. Thermodynamic parameters for the adsorption and activation processes were determined. Galvanostatic polarization data indicated that Schiff base act as a mixed-type inhibitor and the adsorption isotherm obeyed the Langmuir adsorption isotherm. Results obtained from quantum chemical studies show excellent correlations between the quantum chemical parameters and the experimental inhibition efficiencies using density functional theory at the B3LYP/6-31G（d,p） and B3LYP/3-21G basis set levels and ab initio calculations using HF/6-31G（d,p） and HF/3-21G methods.     

Preparation and structural characterization of Zn1?xMnxSe thin films

Undoped and Mn doped ZnSe nanoparticles thin films of thickness ranging from 20 to 120 nm have been successfully synthesized via inert gas condensation (IGC) technique with constant Argon gas flow rate and deposition temperature 300 K. The energy dispersive X-ray analysis (EDX) for freshly deposited Zn_1−xMn_xSe thin films were carried out and revealed that Mn contents (x) were 0, 0.05, 0.16 and 0.25. The as-prepared deposited thin films of different thickness were examined using transmission electron microscope (TEM) and showed that all films were nanocrystalline with particle size ranging from 4.1 to 6.6 nm. The grazing incident in-plane X-ray diffraction (GIIXD) patterns verified nanocrystalline single phase zinc blende structure for 80 nm film thickness for all examined Zn_1−xMn_xSe compound films. A broadening of main characteristic lines (111), (220) and (311) of cubic phase was observed and was attributed to the lower particle size in nanocrystalline examined Zn_1−xMn_xSe compound films.     

Computational Prediction of Resistance Induced Alanine-Mutation in ATP Site of Epidermal Growth Factor Receptor

Epidermal growth factor receptor (EGFR) resistance to tyrosine kinase inhibitors can cause low survival rates in mutation-positive non-small cell lung cancer patients. It is necessary to predict new mutations in the development of more potent EGFR inhibitors since classical and rare mutations observed were known to affect the effectiveness of the therapy. Therefore, this research aimed to perform alanine mutagenesis scanning on ATP binding site residues without COSMIC data, followed by molecular dynamic simulations to determine their molecular interactions with ATP and erlotinib compared to wild-type complexes. Based on the result, eight mutations were found to cause changes in the binding energy of the ATP analogue to become more negative. These included G779A, Q791A, L792A, R841A, N842A, V843A, I853A, and D855A, which were predicted to enhance the affinity of ATP and reduce the binding ability of inhibitors with the same interaction site. Erlotinib showed more positive energy among G779A, Q791A, I853A, and D855A, due to their weaker binding energy than ATP. These four mutations could be anticipated in the development of the next inhibitor to overcome the incidence of resistance in lung cancer patients.