The effect of CuI–PbI2 nanocomposite fabricated by the sonochemical route on electrochemical hydrogen storage characteristics

Hydrogen storage is an essential technique for developing hydrogen technology and electrochemical cells in stable energy, transport, and portable power. Hydrogen holds the maximum specific power of all fuels; nevertheless, its low ambient temperature density occurs in a lower energy density; therefore, there is a need to develop advanced storage procedures that own the potential for greater energy density. Therefore, this research incorporates the fabrication of novel nanocomposite (CuI–PbI₂) by the sonochemical method, architectural, morphological observations, and relevant electrochemical hydrogen storage features. The electrochemical features with different morphology have revealed 515 and 585 mAh/g discharge capacity for bulk and nano-sized samples after 15 cycles, respectively.     

Analysis of spatial transform motion estimation with overlappedcompensation and fractional-pixel accuracy

The authors investigate how the performance of spatial transform motion estimation can be significantly improved by incorporating overlapped compensation and fractional-pixel accuracy. An overlapped spatial transformation (OST) motion model is developed, which successfully addresses the inability of the conventional block matching technique to compensate for complex motion and inside-block motion field discontinuities. Simulation results show that the motion compensated prediction error of this method is reduced by 1.1 dB, compared with the conventional overlapped block matching motion estimation, for the same generated motion vectors overhead. To improve the performance, the overlap must be used in both the motion estimation and compensation processes. Further improvement can be obtained using half-pixel precision motion vectors. However, this improvement is comparatively less than the gain of conventional block matching from a half-pixel search     

Fabrication of PLA/MWCNT/Fe3O4 composite nanofibers for leukemia cancer cells

The efficient delivery of daunorubicin loaded poly (lactic acid) (PLA)/multiwalled carbon nanotubes (MWCNT)/Fe₃O₄ composite nanofibers was investigated. The synthesized nanofibers were characterized using SEM, TEM, and XRD analysis. The proliferation inhibition effect of PLA/MWCNT/Fe₃O₄ nanofibrous scaffolds on leukemia K562 cell lines was investigated. The effect of nanofiber concentration on the daunorubicin delivery in the absence and presence of external magnetic field was also evaluated. The results indicated that the incorporation of daunorubicin into the prepared nanofibrous scaffold under applied magnetic field could have synergistic cytotoxic effect on leukemia cancer cells. The drug release mechanism followed the non-Fickian transport.     

Hydrogenolysis of nitrosodimethyl amine in gas phase over Au/γ-Al2O3 nanocatalyst

Nitrosodimethyl amine (NDMA), as a carcinogenic byproduct in production of unsymmetrical dimethyl hydrazine (UDMH) in space industries, should be decomposed in the vapor phase. A suitable method for this purpose is selective catalytic hydrogenolysis of NDMA over Au/γ-Al₂O₃ nanocatalyst. We synthesized and characterized the Au/γ-Al₂O₃ nanocatalyst by homogeneous deposition-precipitation (HDP)/DP-urea method. Activity of the catalyst was influenced by nanosized Au particles, Au loading and the bed temperature. The optimum parameters for the catalyst were: Au particles <5 nm, Au loading at 1.5 wt% and bed temperature of 35–45 °C. The reaction was strongly sensitive to the Au particle size. The reaction occurred over the catalyst to produce dimethyl amine (DMA) and nitroxyl in a selective manner. The kinetics of NDMA hydrogenolysis over the nanocatalyst was studied in an integral fixed bed reactor. There existed a consistency with the Langmuir-Hinshelwood mechanism involving dissociative adsorption of H₂ and NDMA.     

Microwave-assisted one-pot three-component synthesis of thiazolidinones using KSF@Ni as an efficient heterogeneous catalyst

Convenient, one-pot three-component reaction for the synthesis of thiazolidinones from aldehydes, thiosemicarbazide, and maleic anhydride in the presence of KSF@Ni as heterogeneous catalyst under microwave irradiation was developed. Products were obtained in reasonable yield in short reaction time.     

A successive approximation vector quantizer for wavelet transformimage coding

A coding method for wavelet coefficients of images using vector quantization, called successive approximation vector quantization (SA-W-VQ) is proposed. In this method, each vector is coded by a series of vectors of decreasing magnitudes until a certain distortion level is reached. The successive approximation using vectors is analyzed, and conditions for convergence are derived. It is shown that lattice codebooks are an efficient tool for meeting these conditions without the need for very large codebooks. Regular lattices offer the extra advantage of fast encoding algorithms. In SA-W-VQ, distortion equalization of the wavelet coefficients can be achieved together with high compression ratio and precise bit-rate control. The performance of SA-W-VQ for still image coding is compared against some of the most successful image coding systems reported in the literature. The comparison shows that SA-W-VQ performs remarkably well at several bit rates and in various test images.     

Plasma Stability Evaluation Based on MHD Activity and Hard X-Ray Emission in the IR-T1 Tokamak

Determinations of the poloidal beta, internal inductance, plasma energy, plasma pressure, plasma temperature, plasma resistance, plasma effective atomic number, magneto-hydrodynamics (MHD) activity, Runaway electrons energy and energy confinement time are essential for tokamak experiments and optimized operation. Also some of the plasma information can be deduced from these parameters, such as plasma toroidal current profile, and MHD instabilities. In this contribution we investigated about measurements of some plasma parameters as well as MHD activity and Runaway electrons energy. For this purpose we used the magnetic diagnostics and a hard X-ray spectroscopy in IR-T1 tokamak. A hard X-ray emission is produced by collision of the Runaway electrons with the plasma particles or limiters. The mean energy was calculated from the slope of the energy spectrum of hard X-ray photons. In this paper in order to measure energy of the Runaway electrons, we obtained hard X-ray energy in every 5 ms intervals, from the beginning to the end of plasma. Results indicated mean energy of Runaway electrons is maximum during the 0–5 ms interval.     

Mixed Tabu machine for portfolio optimization problem

In this paper, we introduce a novel artificial neural network (NN) to solve the portfolio optimization problem. The proposed NN is called the Mixed Tabu Machine (MTM) since its structure is similar to the Tabu Machine, but includes both discrete and continuous variables. Similar to the Hopfield network, the state of the MTM is updated to find the global minimum energy state. To escape from local minimum states of the energy in the MTM, the state transition mechanism is controlled by a Tabu search in both discrete and continuous search spaces. The experimental results for five standard benchmark data sets show that the MTM can clearly obtain good results in very small computation time.