Islamic Azad University of Majlesi

This paper describes the development a novel 8,9-dihydroxy-7-methyl-12H-benzothiazolo[2,3-b]quinazolin-12-one-ZnO/CNTs modified carbon paste electrode (DMBQ/ ZnO/CNTs/CPE)for the electrocatalytic determination of hydroxylamine (HX) in the presence of phenol (PL) and sulfite (ST) in water and waste water samples. We describe synthesis and characterization of ZnO/CNTs nanocomposite with different methods such as Scanning electron microscopy (SEM); Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Result shows for the mixture containing HX, PL and ST, the peaks potential well separated from each other. Their square wave voltammetrics (SWV) peaks current increased linearly with their concentration at the ranges of 0.09– 350, 0.5–500 and 0.7–400 μM, respectively with the detection limits of 0.04, 0.1 and 0.3 μM, respectively. The modified electrode was successfully used for the determination of the analytes in real samples with satisfactory result.

This paper presents an adaptive fuzzy sliding-mode controller (AFSMC) based on the boundary layer approach for speed control of an indirect field-oriented control (IFOC) of an induction motor (IM) drive. In general, the boundary layer approach leads to a tradeoff between control performances and chattering elimination. To improve the control performances, a fuzzy system is assigned as reaching control part of the fuzzy sliding-mode so that it eliminates the chattering completely in spite of the large uncertainties in the system. The applied fuzzy controller acts like a saturation function with a nonlinear slope inside thin boundary layer near the sliding surface to guarantee the stability of the system. Moreover, an adaptive law is implemented to estimate the unknown bound of uncertainty, which is obtained in the sense of Lyapunov stability theorem to minimize the control effort. The proposed AFSMC-based IM drive is implemented in real-time using DSP board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed AFSMC-based IM drive at different operating conditions.

This study assessed the use of E-SERVQUAL scale to construct e-Service Quality (e-SQ) for internet banking services. In addition, it attempted to examine the effect of e-SQ on e-Customer Satisfaction (e-CS). Construct of e-SQ for internet banking services was developed to determine dimensions of e-SQ based on the E-SERVQUAL instrument, dimensions used to measure e-SQ in internet banking in USA, Hong Kong, Taiwan, Sweden and UK, and the expert opinions. The primary data of e-SQ and e-CS were gathered from 392 internet banking users, representing 76% response rates, of four main public banks in Iran. The finding indicated that efficient and reliable services, fulfilment, security/trust, site aesthetics, responsiveness/contact, and ease of use constitute e-SQ for internet banking services in Iran; indicating that dimensions and items of E-SERQUAL need to be reorganized and reinterpreted when it is used to measure e-SQ for internet banking. A significant positive relationship exists between e-SQ and e-CSI in the internet banking. The regression analysis performed showed that security/trust, site aesthetics, and ease of use of the internet banking services have positive effects on e-CS.

Cancer is currently one of the main health issues in the world. Among different varieties of cancers, skin cancer is the most common cancer in the world and accounts for 75% of the world's cancer. Indeed, skin cancer involves abnormal changes in the outer layer of the skin. Although most people with skin cancer recover, it is one of the major concerns of people due to its high prevalence. Most types of skin cancers grow only locally and invade adjacent tissues, but some of them, especially melanoma (cancer of the pigment cells), which is the rarest type of skin cancer, may spread through the circulatory system or lymphatic system and reach the farthest points of the body. Many papers have been reviewed about the application of image processing in cancer detection. In this paper, the automatic skin cancer detection and also different steps of such a process have been discussed based on the implantation capabilities.

A carbon paste electrode (CPE) was modified by incorporation of carbon nanotubes and ferrocene (FC) and studied in pH 7.0 phosphate buffer solution (PBS) by cyclic voltammetry (CV). The modified electrode showed an excellent electrocatalytic effect on the oxidation of norepinephrine (NE). In PBS of pH 7.0, the oxidation current increased linearly with concentration of NE from 0.47 to 500.0 μmol L−1. The detection limit (3σ) obtained by differential pulse voltammetry (DPV) was 0.21 μmol L−1. Then the modified electrode was used to determine NE in an excess of acetaminophen (AC) and tryptophan (TRP) by DPV. Finally, this method was used for the determination of NE, AC and TRP in some real samples.

<p>Polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) composites have attracted considerable attention due to the synergic relation between the two polymers and developing novel blends with improved properties. On one hand, PVA is a versatile polymer with higher mechanical properties compared to CMC. On the other hand, CMC has high biodegradability and biocompatibility, while suffering from poor mechanical properties. Therefore, the blending of the two polymers can help to benefit from the individual component properties. This paper has reviewed the properties and potential applications (e.g. drug delivery, food packaging, and agriculture) of the PVA/CMC composites.</p>

In this paper, we address the problem of recovering degraded images using multivariate Gaussian mixture model (GMM) as a prior. The GMM framework in our method for image restoration is based on the assumption that the accumulation of similar patches in a neighborhood are derived from a multivariate Gaussian probability distribution with a specific covariance and mean. Previous methods of image restoration with GMM have not considered spatial (geometric) distance between patches in clustering. Our conducted experiments show that in the case of constraining Gaussian estimates into a finite-sized windows, the patch clusters are more likely to be derived from the estimated multivariate Gaussian distributions, i.e., the proposed statistical patch-based model provides a better goodness-of-fit to statistical properties of natural images. A novel approach for computing aggregation weights for image reconstruction from recovered patches is introduced which is based on similarity degree of each patch to the estimated Gaussian clusters. The results admit that in the case of image denoising, our method is highly comparable with the state-of-the-art methods, and our image interpolation method outperforms previous state-of-the-art methods.

A ferrocene modified carbon nanotubes paste electrode (FCMCNTPE) was constructed and used as a fast and sensitive tool for the determination of N-acetylcysteine (NAC) at trace level. It has been shown by direct current cyclic voltammetry and double step chronoamperometry that this sensor can catalyze the oxidation of NAC in phosphate buffer solution (PBS) and produces a sharp oxidation peak current. Linear calibration ranges were 1.0-400.0 µmol L-1 with detections limit of 0.6 µmol L-1 for differential pulse voltammetry. Finally, the sensor was also examined as a selective, simple and precise new electrochemical sensor for the determination of NAC in real samples such as drug, serum and urine.

NiTi is an alloy of nickel and titanium with important characteristics such as shape memory, superelasticity, high electrical resistance, high corrosion resistance, long fatigue life, and vibration absorption. The unique features of this alloy have made it useful in all types of industries. However due to these same characteristics, it is difficult to perform machining and forming operations on this alloy by traditional methods. One of the machining techniques suitable for NiTi alloy is electro discharge machining. The electro discharge machining process is one of the most practical nontraditional machining methods which are not influenced by the hardness and physical properties of the workpiece. This research intends to study the effects of electro discharge machining parameters such as voltage, discharge current, pulse on time and pulse off time on the rate of material removal, tool wear, relative electrode wear and surface roughness of NiTi alloy. For the design of experiments, the Taguchi’s method for the design of experiments, L18 orthogonal array and the ‘Minitab’ software program have been used. The experiments indicate that the parameters of discharge current, voltage, and pulse on time have a direct impact on material removal rate (MRR), and with their increase, MRR increases as well. Tool wear rate (TWR) diminishes with the increase of pulse off time and discharge current. The analysis of results obtained for surface roughness indicates that pulse on time and off time have the highest impact on the surface roughness of NiTi alloy.

Today’s fashion clothing market is highly competitive and the textile and clothing industry is a significant area of the world’s economy. In addition, the sustainability issues have received a lot of attention in the textile supply chains. Since supplier evaluation and selection is a crucial decision in supply chain management, this paper proposes a framework for textile suppliers’ sustainability evaluation criteria and a new model based on this framework onto ranking a given list of suppliers. The relative importance of criteria and the suppliers’ performance with respect to criteria are considered based on decision-makers’ preferences in the model. To cope with the subjectivity of decision-makers’ opinions, fuzzy set theory has been applied and a modular model on the basis of Fuzzy Inference System is proposed. A real-life supplier selection problem for the textile industry is utilized to show the feasibility of the proposed model. Validation of the proposed model is studied through an existing literature model. The results show the effectiveness of the proposed model.

Considering the significant position of critical pedagogy in teaching English as a foreign language, there is a need for in-depth investigations of novice teachers' professional identity construction through the interaction with critical notions introduced in teacher education programs. As the impact of such programs on novice teachers' professional identity in an EFL context has remained underexplored, this study intends to address the gap. This study examines the role of a teacher education program informed by the principles of critical pedagogy in influencing novice EFL teachers' professional identity construction. Participants were 9 novice EFL teachers whose process of professional identity construction was analysed through reflective journals, class discussions, and semi-structured interviews before and after the program. Results of the study revealed two major shifts in participants' professional identity. Before the program their identity was characterized by "an attitude of compliance" and "a narrow view of EFL teaching". However after the program they "developed voice" and "adopted a humanistic conception of teaching".

In this study, the microstructural evolutions and corrosion resistance of aluminium/copper joint fabricated through explosive welding process have been thoroughly investigated, while stand-off distance was variable. Microstructural analyses demonstrate that, regardless of grain refinement in the welding boundary, increasing the stand-off space is followed by a higher thickness of the localized melting pool. X-Ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) analyses recognized the binary intermetallic layers as a combination of Al2Cu and AlCu. Polarization and electrochemical impedance spectroscopy (EIS) corrosion tests revealed that a higher stand-off distance resulted in the increment of corrosion potential, current rate, and concentration gradient at the interface owing to the remarkable kinetic energy of the collision, which impaired corrosion resistance.

This paper proposes a new optimal method for the parameter identification of a proton exchange membrane fuel cell (PEMFC) for increasing the model accuracy. In this research, a new improved version based on deer hunting optimization algorithm (DHOA) is applied to the Convolutional neural network for the PEMFC parameters identification purpose. Indeed, the method is implemented to develop the method performance for estimating the PEMFC model parameters. The method is then validated based on 4 operational conditions. Experimental results declared that utilizing the proposed method gives a prediction with higher accuracy for the parameters of the PEMFC model.

In the present work, for the first time, laminar natural convection of water-TiO2 nanofluid around a hot obstacle in a square cavity is simulated by Lattice Boltzmann Method (LBM). The effect of Rayleigh number, obstacle dimension, volume fraction of nanofluid, cavity dimensions, surface ratio and various models for computing of thermal conductivity coefficient and viscosity coefficient on Nusselt number and heat transfer around hot obstacle in enclosure has been investigated. The results show that by increase in Rayleigh number and volume fraction, average Nusselt number will increase. The average Nusselt number will increase when obstacle dimensions increase to 0.5 L but it will decrease when the obstacle dimensions increase to 0.7 L. Vortexes will create in 0.8 L and it causes to increase heat transfer. By reduplicating the obstacle width, heat transfer is better than reduplicating the obstacle length. The average Nusselt number increases by increase in cavity length and it will decrease by increase in cavity wide. All results are equal in Hamilton-Crosser and Maxwell-Garnett model when the surface ratio is one. But heat transfer will increase by decreasing surface ratio. The average Nusselt number in Wang model is less than Nusselt number in Brinkman model. Keywords: Natural convection, Nanofluid, Viscosity coefficient, Thermal conductivity coefficient, Lattice Boltzmann method

Researches on mobile robot path planning with meta-heuristic methods to improve classical approaches have grown dramatically in the recent 35 years. Because routing is one of the NP-hard problems, an ant colony algorithm that is a meta-heuristic method has had no table success in this area. In this paper, a new approach for solving mobile robot navigation in dynamic environments, based on the heuristic feature of an optimized ant colony algorithm is proposed. Decision-making influenced by the distances between the origin and destination points and the angle variance to the nearest obstacles. Ideal paths are selected by the fuzzy logic. The proposed ant colony algorithm will optimize the fuzzy rules' parameters that have been using to On-line (instant) path planning in dynamic environments. This paper presents a new method that can plan local routs all over the area and to guide the moving robot toward the final track. Using this algorithm, mobile robots can move along the ideal path to the target based on the optimal fuzzy control systems in different environments, especially in dynamic and unknown environments.

histogram which can be modeled as a mixture of two Gaussian density functions, estimating these densities inpractice is not simply feasible. The objective of this paper is to use adaptive particle swarm optimization (APSO) forthe suboptimal estimation of the means and variances of these two Gaussian density functions; then, the computationof the optimal threshold value is straightforward. The comparisons of experimental results in a wide range of complexbimodal images show that this proposed thresholding algorithm presents higher correct detection rate of object andbackground in comparison to the other methods including Otsu’s method and estimating the parameters of Gaussiandensity functions using genetic algorithm (GA). Meanwhile, the proposed thresholding method needs lower executiontime than the PSO-based method, while it shows a little higher correct detection rate of object and background, withlower false acceptance rate and false rejection rate.

Abstract The corrosion behavior and microstructural changes in explosively welded AA5083/AA1050/SS 321 multilayer tubes after heat treatment were studied. Heat treatment were performed in 350 and 450 °C for 6 and 8 h. Microscopic results indicated significant changes in the thickness and concentration of alloying elements in locally melting zone with heat treatment temperature. According to electrochemical tests results at samples interfaces, by increasing the temperature and time of the heat treatment process, the energy stored due to explosive welding is reduced, the difference in the concentration of aluminum related to steel in the interface layer decreases, and the corrosion rate (current density) and electrical charge transfer decrease.

Carbon nanotubes (CNTs)-reinforced aluminum composites have attracted attention due to their high specific strength low density, which makes them suitable for the use in aerospace and automobile industries. In this review, preparation methods of Al/CNTs composites for achieving a homogeneous desperation of the CNT in the Al matrix are summarized. In addition, the effect of processing methods on carbon nanotube distribution and enhancement of mechanical properties such as toughness, wear behavior and hardness of the nanocomposites are reviewed. Improvement of mechanical characteristics was observed by the incorporation of carbon nanotubes in aluminum matrix. The strengthening factors gained by the carbon nanotubes addition are the interface of metal and CNTs and the chemical and structural stability of CNTs.

In this research, the effect of stand-off distance on the interfacial mechanical and metallurgical properties of explosively bonded 321 austenitic stainless steel to 1230 aluminum alloy tubes was investigated. Interfacial microstructure was evaluated by optical microscopy and scanning electron microscope. Also, Microhardness tests were also carried out. The results show that with increasing of stand-off distance from 1 mm to 2.5 mm, thickness of intermetallic compounds at the interface increased from 3.5 µm to 102.3 µm, and also shape of interface was transited from smooth to wavy. The microhardness of the sample with 1 mam stand-off distance was 650 HV that increased to 927 HV in the sample with 2.5 mm stand-off distance which is related to intermetallic amount. The proportional amount of strength were 103.2 MPa and 214.5 MPa in the above samples respectively.

A microwave photonic in-phase and quadrature detector is conceived and practically demonstrated. The detector has the ability to become electronically reconfigured to operate at any frequency over a wide range. This makes it an excellent candidate for frequency agile radars and other electronic warfare systems based on frequency hopping. The detector exhibits a very low amplitude and phase imbalance, which removes the need for any imbalance compensation technique. The system is designed based on the transversal filtering concept and reconfigurability is achieved via wavelength control in a dispersive fiber. The system operation was demonstrated over a frequency range of 3.5-35 GHz, with a maximum of -32 dB amplitude imbalance.