Microstructure investigation and thermal stability of 99.1% aluminum processed by equal channel angular extrusion

Microstructure evolution of 99.1% aluminum after equal-channel angular extrusion (ECAE) and subsequent heat-treatment was investigated. After deformation the samples were annealed at different temperatures. The deformed and annealed states were characterized by Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and microhardness tests. It was shown that the observed microstructure changes during subsequent annealing have to be associated with recovery and cells formation. The initial stages of recovery were investigated using weak-beam technique. The microstructure obtained after annealing for 1 h at 100 °C consists of some arrangements of the dislocations into sub-grain boundaries within the wide preexisting grains. Annealing at 300 °C led to the appearance of a duplex microstructure consisting of bands of slightly coarsened grains associated with refined grains. No growth of dislocation cells was observed up to 400 °C. In XRD measurements, the lattice parameter increase with subsequent heating. This indicates a continuous grain growth during annealing. This is due to the important increase of coherency length, D observed parallel to a substantial decrease of rms-strain, ε.     

Epoxidized polyurethaneamide and polyesteramide as petroleum pipeline coatings

Linseed oil fatty acids were epoxidized by peracetic acid, then reacted with diethanolamine to give epoxidized hydroxy ethyl linseed oil fatty acid amide ( I ). This amide was rejected with toluene diisocyanate to produce epoxidized polyurethane-amide ( II ). Component I was also reacted with phthalic anhydride to give epoxidized polyesteramide ( III ). Resins II and III were evaluated as coating materials. The results obtained were compared with commercial epoxy resin, and show that resins II and III may be suitable to use as petroleum pipeline coatings.     

Studies on Sulfamethazine - Lysozyme Interactions by Fluorescence Quenching

The binding of sulfamethazine to lysozyme was investigated in relation to certain physicochemical parameters by a fluorescence quenching technique. The parameters considered are ionization of the drug, hydrogen-ion concentration and alteration in protein conformation induced by urea at different pH-levels. The binding constant of the drug was found to be pH-dependent, increasing as the pH is reduced from 9 to 5. On the other hand, denaturation of lysozyme with urea favors the binding process. The interaction being again more pronounced at the lower pH's, when the drug is in the unionized form, and depends also upon the extent of denaturation of the enzyme.

Graphic representation, as well as, computer analysis of the different corrected binding data, at high drug to protein ratios are strongly indicative of a 1:1 interactions. The nature of the binding forces, and changes in the binding constants associated with alteration in the ionization of sulfamethazine at various pH-points were further interpreted in terms of hydrogen-ion dissociation equilibrium of the drug     

Inhibition of the corrosion of steel by acid dihydrazides

The corrosion inhibitory properties of homologous series of acid dihydrazides were studied. Gasometry, potentiodynamic polarization and impedance measurements were recorded for mild steel specimens immersed in 1.0 M H₂SO₄ or a mixture of 1.0 M H₂SO₄ + 1.0 M Na₂SO₄ having the same ionic strength with a pH range from zero to 7. Effect of presence of different concentrations of oxalic, malonic, succinic or pimelic dihydrazide on the corrosion rate of steel in the above solutions were investigated. The results indicated that the protection efficiency of the acid dihydrazides increased with the increase of the number of the methylene groups in the acid dihydrazide molecule. The results are discussed on the basis of the change of each, of the electron density of the donating atoms, of the inhibitor molecules, and the orientation of the inhibitor at the metal surface with the molecular structure of the inhibitor.     

An efficient routing protocol for cognitive radio networks of energy-limited devices

Telecommunication Systems - In the era of Internet-of-things (IoT), the future 5G networks are supposed to provide ubiquitous connectivity, high speed, as well as low latency and energy efficiency...     

Lower-bound time-complexity greening mechanism for duplication-based scheduling on large-scale computing platforms

The Journal of Supercomputing - Large-scale computing platforms become essential in nowadays business and scientific activities. The electrical energy consumed by such platforms increases...     

Emotion Recognition from Occluded Facial Images Using Deep EnsembleModel

Facial expression recognition has been a hot topic for decades, but high intraclass variation makes it challenging. To overcome intraclass variation for visual recognition, we introduce a novel fusion methodology, in which the proposed model first extract features followed by feature fusion. Specifically, RestNet-50, VGG-19, and Inception-V3 is used to ensure feature learning followed by feature fusion. Finally, the three feature extraction models are utilized using Ensemble Learning techniques for final expression classification. The representation learnt by the proposed methodology is robust to occlusions and pose variations and offers promising accuracy. To evaluate the efficiency of the proposed model, we use two wild benchmark datasets Real-world Affective Faces Database (RAF-DB) and AffectNet for facial expression recognition. The proposed model classifies the emotions into seven different categories namely: happiness, anger, fear, disgust, sadness, surprise, and neutral. Furthermore, the performance of the proposed model is also compared with other algorithms focusing on the analysis of computational cost, convergence and accuracy based on a standard problem specific to classification applications.     

Standalone noise and anomaly detection in wireless sensor networks: A novel time-series and adaptive Bayesian-network-based approach

Wireless sensor networks (WSNs) consist of small sensors with limited computational and communication capabilities. Reading data in WSN is not always reliable due to open environmental factors such as noise, weakly received signal strength, and intrusion attacks. The process of detecting highly noisy data is called anomaly or outlier detection. The challenging aspect of noise detection in WSN is related to the limited computational and communication capabilities of sensors. The purpose of this research is to design a local time-series-based data noise and anomaly detection approach for WSN. The proposed local outlier detection algorithm (LODA) is a decentralized noise detection algorithm that runs on each sensor node individually with three important features: reduction mechanism that eliminates the noneffective features, determination of the memory size of data histogram to accomplish the effective available memory, and classification for predicting noisy data. An adaptive Bayesian network is used as the classification algorithm for prediction and identification of outliers in each sensor node locally. Results of our approach are compared with four well-known algorithms using benchmark real-life datasets, which demonstrate that LODA can achieve higher (up to 89%) accuracy in the prediction of outliers in real sensory data.     

Enhanced EDCA with Deterministic Transmission Collision Resolution for Real-Time Communication in Vehicular Ad Hoc Networks

The collision prevention system is one of most important research issues on vehicle safety technology. Sending worming messages within the right time and reliable transmission will get prevention of a possible vehicle accident. The communication standards of vehicular networks (VANET) are unable to guarantee the delivery of critical messages within tight deadlines. Indeed, the transmission collisions are handled with probabilistic manner that can reduce the transmission latency; however, it is inept to predict an upper bound value of this delay to verify the deadline. In this paper, we propose a medium access protocol that ensures the delivery of critical messages within a deadline. It is a hard real-time system with delay constant guarantee. We are focusing on improving the EDCA medium access protocol to prioritize critical messages and to get access to the transmission channel within a predictable communication delay. We create a new enhanced access protocol that is compatible with the IEEE 802.11p VANET standards and adapted to real-time communication requirements related to the vehicle collision avoidance problem.     

In vivo study of hybrid biomaterial scaffold bioactive glass–chitosan after incorporation of Ciprofloxacin

The present study aimed to evaluate the effect of bioactive glass as well as the presence of Ciprofloxacin drug (%Cip) into bioactive glass–chitosan composite on the in vivo behavior of these scaffolds. These scaffolds were implanted in the femoral condyl of an ovariectomized rat. The serum and organs (liver and kidney) of the under investigated rats were analyzed. Also the physicochemical properties of the prepared implants were assessed using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) before and after implantation (at different periods of implantation). Biochemical and histological analyses of the under investigated rats proved the biocompatibility of the prepared scaffolds. The hydroxyapatite like layer was significantly precipitated on the surface of BG–CH scaffold than BG–CH–20Cip. In this same period, FT-IR of BG–CH shows complete disappearance of Si–O–Si. Their characteristics bands were replaced by P–O group arisen form bone apatite bands. Physicochemical results show progressive degradation of BG–CH and BG–CH–20Cip that occurred at the same time as replacement of the implant by an apatite layer. However, the bioresorbability and bioactivity of BG–CH are faster than those of BG–CH–20Cip. Therefore, the incorporation of the Ciprofloxacin in the BG–CH induces a retarding effect on the formation of the hydroxyapatite, and consequently on the ossification, without any side effects on the liver–kidney.