Trace elements‐based Auroshell gold@hematite nanostructure: Green synthesis and their hyperthermia therapy

Hyperthermia is an additional treatment method to radiation therapy/chemotherapy, which increases the survival rate of patients without side effects. Nowadays, Auroshell nanoparticles have attracted much attention due to their precise control over heat use for medical purposes. In this research, iron/gold Auroshell nanoparticles were synthesised using green nanotechnology approach. Auroshell gold@hematite nanoparticles were synthesised and characterised with rosemary extract in one step and the green synthesised nanoparticles were characterised by X‐ray powder diffraction, SEM, high‐resolution transmission electron microscopy, and X‐ray photoelectron spectroscopy analysis. Cytotoxicity of Auroshell iron@gold nanoparticles against normal HUVEC cells and glioblastoma cancer cells was evaluated by 2,5‐diphenyl‐2H‐tetrazolium bromide method, water bath hyperthermia, and combined method of water bath hyperthermia and nano‐therapy. Auroshell gold@hematite nanoparticles with minimal toxicity are safe against normal cells. The gold shell around the magnetic core of magnetite caused the environmental and cellular biocompatibility of these Auroshell nanoparticles. These magnetic nanoparticles with targeted control and transfer to the tumour tissue led to uniform heating of malignant tumours as the most efficient therapeutic agent.     

Improvement to speech-music discrimination using sinusoidal model based features

This paper addresses a model-based audio content analysis for classification of speech-music mixed audio signals into speech and music. A set of new features is presented and evaluated based on sinusoidal modeling of audio signals. The new feature set, including variance of the birth frequencies and duration of the longest frequency track in sinusoidal model, as a measure of the harmony and signal continuity, is introduced and discussed in detail. These features are used and compared to typical features as inputs to an audio classifier. Performance of these sinusoidal model features is evaluated through classification of audio into speech and music using both the GMM (Gaussian Mixture Model) and the SVM (Support Vector Machine) classifiers. Experimental results show that the proposed features are quite successful in speech/music discrimination. By using only a set of two sinusoidal model features, extracted from 1-s segments of the signal, we achieved 96.84% accuracy in the audio classification. Experimental comparisons also confirm superiority of the sinusoidal model features to the popular time domain and frequency domain features in audio classification.     

Compact Dual Band-Notched Monopole Antenna with Modified Radiating Patch for UWB Wireless Applications

Ultra-wideband (UWB) planar antennas with single or multiple notched frequency bands properties have recently been considered for various communications between wireless devices. In this study, a low profile microstrip monopole antenna with double band-filtering function is designed and investigated. FR-4 dielectric with properties of ε = 4.4 and δ = 0.02 has been employed as the antenna substrate. The configuration of the proposed design is composed of a modified fork-shaped radiating patch with inverted Ω-shaped slot and a pair of coupled Γ-shaped parasitic structures, a feed-line and a ground plane. The proposed dual band-notched UWB antenna provides good impedance bandwidth characteristic from 2.89 to 12.43 GHz for VSWR <2 with two notched bands which cover all the 5.2/5.8 GHz of WLAN, 3.5/5.5 GHz of WiMAX and 4-GHz of C bands ranges. The antenna provides good radiation behavior with sufficient gain levels over its operation frequency band.     

Micro-optical probe model using integrated triple microring resonators for vertical depth identification

Microsystem Technologies - The nonlinear microring resonator system is designed and the triple vertically Panda rings arranged for 3D imaging probe generation. The required whispering gallery modes...     

Improvement of Solar Cell Performance After Oxygen Removal by Electron Beam Melting

Two 450 kg multicrystalline silicon ingots were obtained by mixing and melting high purity silicon and silicon from the edges and the bottom of the casted ingots together in a casting furnace. For one of the ingot, the silicon from casted ingots was refined in an electron beam melting furnace to remove oxygen. The oxygen content was reduced from 10 to less than 0.0517 ppmw when silicon was refined at 500 kW with removal efficiency up to 99.429% in the most areas. The life time of the ingot after oxygen removal was measured to be far better than another one, whereas in the central parts the value was almost 6.7 µs. The efficiencies of both solar cells were initially 17.55% but after 4 h decreased to 17.05% and 15.55%, respectively. The solar cell after oxygen removal shows a better performance in degradation.     

Effects of shadowing on the number of active users in random multi-user channels

Prior work has addressed the effects of multipath fading and path loss separately for broadcast and multiple-access channels. It has been shown that the number of simultaneously active users are of the order \(\Theta (\ln (\ln (n)))\) for random channel gains with exponentially-decaying tails, where n is the total number of users. Furthermore, it has been shown that assuming path loss is dominant and ignoring multipath fading, the user capacity (i.e. the maximum number of simultaneously active users in a wireless system) of multi-user channels is of the order \(\Theta (\ln (n))\) when the users are spatially distributed on the plane with a Gaussian or Uniform distribution. In this paper, we study the shadowing effects on the number of active users for broadcast and multiple-access channels in which the users are randomly distributed on the plane. It is shown that as the total number of users in the multi-user channel goes to infinity, the number of active users is of the order \(\Theta (\sqrt{\ln (n)}).\)     

Effect of the Synthesis Method on Co-catalysts Based on MCM-41 for the Fischer–Tropsch Reaction

In this work, cobalt catalysts based on ordered mesoporous materials of the MCM-41 type were synthesized and characterized. The synthesis of the catalysts was performed by using different methods: impregnation; incorporation of the metal in the synthesis gel and ionic exchange of the metal by the template. Different characterization techniques were used (N₂ adsorption–desorption, XRD, TPR, SEM and XPS) to study the textural and structural properties of the samples and the metal-support interaction corresponding to each method of synthesis. These samples were tested in the CO Hydrogenation (Fischer–Tropsch Synthesis) by measuring the CO conversion and the selectivity to CO₂ and some groups of hydrocarbons chains. The results show that structural and textural properties as well as the metal-support interactions are affected by the synthesis method. According to this study, catalytic performance is related to the properties of the samples, observing that the metal support interaction highly affects the activity and selectivity of the catalysts.     

Approximate Torsional Analysis of Multi-layered Tubes with Non-circular Cross-Sections

In this paper an approximate formulation for torsional analysis of tubes with multi-layered non-circular cross-sections is presented. A previously presented method based on Bredt’s theory is extended to achieve these formulas. Layers are assumed to be isotropic and may possess different thicknesses and material properties. The obtained formulas for shear stress and angle of twist are applicable to thin to moderately thick closed cross-sections. It is shown that depending on the properties of the layers, maximum shear stress does not necessarily happen on the outer boundary. Furthermore, the effect of different cross-sectional shapes on torsional response is studied. Using the presented method, one can achieve desirable shear stresses and angles of twist for a polygonal multi-layered tube with a proper choice of bluntness. The method can be extended for torsion problem of FGM tubes as well. The presented formulas for torsion problem are relatively accurate and suitable to be implemented in optimization programs.     

Rotation and gray-scale-invariant texture analysis using radon and differential radon transforms based hidden Markov models

This study carries out rotation and gray-scale-invariant texture analysis of the textures in Brodatz album. A radon and differential radon transform based technique has been proposed to extract the features of the different textures at different orientations. These features have been used to train one-dimensional hidden Markov models - one for each texture. Testing and classification was done using percentage of correct classification (PCC) as figure of merit. The best percentage achieved was 99.9%.     

Synthesis of Er2O3 Nanoparticles and Er2O3 Nanoparticle/Polyaniline Deposition on the Surface of Stainless Steel by Potentiostatic Deposition

Erbium oxide nanoparticles (Er₂O₃ NP) were synthesized with an efficient method in the presence and absence of sodium dodecylsulfate (SDS) as surfactant. The effect of SDS on the morphology of the synthesized Er₂O₃ NP is described. The NP were studied through scanning electron microscopy and X‐ray diffractometry. Then, polyaniline and a hybrid material of polyaniline/Er₂O₃ NP were deposited directly on a stainless steel wire by the potentiostatic process. The electrochemical data and scanning electron microscopic studies of polyaniline and its nanocomposite on the stainless steel wire demonstrate the influence of the synthesized Er₂O₃ NP on the electrodeposition of polyaniline. The presence of NP in the electrolyte solution during electrodeposition of polyaniline creates a nanocomposite with a more porous structure than pure polyaniline.