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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Progress in Color, Colorants and Coatings
- نوع مقاله: Journal Article
- کلمات کلیدی: Methyl orange,Modification,TiO2 nanoparticles,Surface,5,Sulfosalicylic acid
- چکیده:
- چکیده انگلیسی: Titanium dioxide nanoparticles surface-modified by 5-sulfosalicylic acid 5-SA-TiO2 were prepared in ethanol by the chemisorption process. The effects of surface improvement on the photocatalytic degradation and adsorption of methyl orange MO were studied in a batch system by considering the various parameters, such as contact time, adsorbent dosage, pH, initial dye concentration and temperature. The adsorption and photocatalytic degradation kinetics of MO using the improved nanoparticles have also been investigated. The results show that the adsorption and photocatalytic degradation processes were good fit with the pseudo-second-order kinetic model R2 0.99. In addition, the equilibrium data for the adsorption process have been evaluated using Langmuir, Freundlich and Temkin isotherms. The adsorption isotherm of MO onto modified TiO2 nanoparticles fitted into the Temkin equation.
- انتشار مقاله: 11-10-1348
- نویسندگان: A. Mohammadi,A. Aliakbarzadeh Karimi,H. Fallah Moafi
- مشاهده
- جایگاه : پژوهشی
- مجله: AUT Journal of Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Nonlinear buckling,size effect,Nanomechanics,Piezoelectric material,Surface elasticity theory
- چکیده:
- چکیده انگلیسی: In this paper, the nonlinear instability of piezoelectric cylindrical nanoshells under the combined radial compression and electrical load including the effects of surface free energy is studied. To consider the surface effects, the Gurtin-Murdoch elasticity theory is utilized along with the classical shell theory to develop an efficient size-dependent shell model. To satisfy the balance conditions on the surfaces of nanoshells, a linear variation of normal stress is assumed through the thickness of the bulk. Electrical field is also exerted along the transverse direction. Based on the virtual work principle, the size-dependent nonlinear governing differential equations are derived in which transverse displacement and Airy stress function are considered as independent variables. After that, a boundary layer theory is used incorporating the surface free energy effects in conjunction with the nonlinear prebuckling deformation, the large deflections in the postbuckling regime, and the initial geometrical imperfection. Finally, a two-stepped singular perturbation technique is employed to obtain the size-dependent critical buckling pressure and the associated postbuckling equilibrium path for alternative electrical loadings. It is revealed that the electrical load increases or decreases the critical buckling pressure and critical end-shortening of nanoshell which depends on the sign of applied voltage. Moreover, it is found that by taking surface free energy effects into account, the influence of electrical load on the postbuckling behavior of nanoshell increases.
- انتشار مقاله: 15-08-1396
- نویسندگان: S. Sahmani,M. Mohammadi Aghdam,A. Akbarzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of AI and Data Mining
- نوع مقاله: Journal Article
- کلمات کلیدی: Stability Analysis,indirect adaptive control,neuro-fuzzy approximators,uncertainty estimation,reconstruction error
- چکیده:
- چکیده انگلیسی: This paper presents an indirect adaptive system based on neuro-fuzzy approximators for the speed control of induction motors. The uncertainty including parametric variations, the external load disturbance and unmodeled dynamics is estimated and compensated by designing neuro-fuzzy systems. The contribution of this paper is presenting a stability analysis for neuro-fuzzy speed control of induction motors. The online training of the neuro-fuzzy systems is based on the Lyapunov stability analysis and the reconstruction errors of the neuro-fuzzy systems are compensated in order to guarantee the asymptotic convergence of the speed tracking error. Moreover, to improve the control system performance and reduce the chattering, a PI structure is used to produce the input of the neuro-fuzzy systems. Finally, simulation results verify high performance characteristics and robustness of the proposed control system against plant parameter variation, external load and input voltage disturbance.
- انتشار مقاله: 27-09-1393
- نویسندگان: M. Vahedi,M. Hadad Zarif,A. Akbarzadeh Kalat
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of AI and Data Mining
- نوع مقاله: Journal Article
- کلمات کلیدی: Artificial Neural Network,Taguchi Method,Analysis of Variance,EMG signals
- چکیده:
- چکیده انگلیسی: This paper presents an application of design of experiments techniques to determine the optimized parameters of artificial neural network (ANN), which are used to estimate force from Electromyogram (sEMG) signals. The accuracy of ANN model is highly dependent on the network parameters settings. There are plenty of algorithms that are used to obtain the optimal ANN setting. However, to the best of our knowledge they did not use regression analysis to model the effect of each parameter as well as present the percent contribution and significance level of the ANN parameters for force estimation. In this paper, sEMG experimental data are collected and the ANN parameters based on an orthogonal array design table are regulated to train the ANN. Taguchi help us to find the optimal parameters settings. Next, analysis of variance (ANOVA) technique is used to obtain significance level as well as contribution percentage of each parameter to optimize ANN’s modeling in human force estimation. The results indicated that design of experiments is a promising solution to estimate the human force from sEMG signals.
- انتشار مقاله: 31-01-1394
- نویسندگان: V. Khoshdel,A. R Akbarzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nanoscience and Nanotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Electron microscopy,Green synthesis,Platinum nanoparticles,Sheep milk,Physicochemical characterization
- چکیده:
- چکیده انگلیسی: Bio-directed synthesis of nanoparticles is an interesting field of rapid advancement for biologists,
chemists and materials scientists, especially in light of efforts to find out green methods of inorganic
material synthesis. In the present study, green synthesis of platinum nanoparticles (PtNPs) using sheep
milk is reported for the first time. By adjusting the concentrations of chloroplatinic acid (H2PtCl6) and
milk in aqueous solutions, spherical PtNPs were obtained at room temperature. The nanoparticles
obtained were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), high-resolution
Transmission Electron Microscopy (TEM) and X-Ray diffraction (XRD). The spherical particles obtained
have an average size 9.0 nm as shown by XRD pattern and TEM analysis. Fourier Transform Infra-Red
(FTIR) measurements were carried out to identify the possible biomolecules responsible for capping and
efficient stabilization of the PtNPs synthesized by milk. The carboxylic acid group libration and amide I
and II bands revealed the binding of protein with platinum surface through the amine group rather than
the carboxyl group. Among a wide variety of biological resources which are introduced for reducing Pt
ions into PtNPs, green approaches like using sheep milk have outstanding benefits for synthesize
biological metal nanoparticles due to their eco-friendly phenomenon and very less amounts of
cytotoxicity. PtNPs green synthesized in this study are potential candidates to use in drug discovery and
gene transfer technologies.- انتشار مقاله: 10-10-1393
- نویسندگان: M. Gholami-Shabani,Z. Gholami-Shabani,M. Shams-Ghahfarokhi,A. Akbarzadeh,Gh. Riazi,M. Razzaghi-Abyaneh
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nanoscience and Nanotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: L-arginine,Functionalization,L-Aspartic acid,Gold Nanoparticles (GNPs)
- چکیده:
- چکیده انگلیسی: Synthesis and characterization of two functionalized gold nanoparticles by using of two poly functional amino acids (L-Arginine and L-Aspartic acid) are reported. The gold nanoparticles were reduced by sodium citrate and functionalized with L-Arginine at the pH of 7 and 11 and L-Aspartic acid at the pH of 7. Transmission electron microscopy, UV-Vis spectroscopy, dynamic light scattering, zeta potential and agarose gel electrophoresis techniques were used for characterization and identification. The transmission electron microscopy image showed well distributed particles with an average size of about 10 nm. At the pH of 7, the results obtained, verified that the interaction between L-Arginine and gold nanoparticles was electrostatic and it was covalent/coordinate in the case of L-Aspartic acid. The functionalized gold nanoparticles possessing free amine and carboxylic groups (poly functional amino acid) could play an important role in conjugating biomolecules such as proteins (e.g. antibodies) and DNA in nanomedicinal and nanobiotechnological applications. In addition, if the pH of the target in vivo environment is constant, functionalized gold nanoparticles bound electrostatically will be preferred. On the other hand, if the pH of the target in vivo environment is variable, then amino acid capped gold nanoparticles bound covalently/coordinately are recommended.
- انتشار مقاله: 11-08-1389
- نویسندگان: D. Zare,A. Akbarzadeh,N. Bararpour
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Rat,Oat extract,Sciatic nerve injury
- چکیده:
- چکیده انگلیسی: Peripheral nerve disorders are the most common neurological problems; therefore, it is important to intervene to treat or stop the resulting side effects. This study aimed to investigate the effect of oat extract on experimental sciatic nerve injury in rats. Totally, 50 adult male rats were divided into five groups (n=10). Group 1 was exposed to sham condition, and group 2 was regarded as the control group (nerve injury without treatment). Moreover, groups 3-5 were subjected to sciatic nerve injury, and they received oral gavages of the oat extract (100, 200, and 400 mg/kg), respectively. Subsequently, 2 and 4 weeks later, the rats were euthanized for pathological evaluation of nerve repair. The results showed an increase in the formation of the perineurium and epineurium dose in the oat-treated groups (100, 200, and 400 mg/kg), compared to the control group after 2 weeks (P<0.05). Furthermore, the presence of inflammatory cells in the oat extract-treated groups (100, 200, and 400 mg/kg) decreased, compared to that in the control group after 2 weeks (P<0.05). In addition, the swelling of the axon significantly decreased in the oat extract-treated groups (200 and 400 mg/kg), compared to the control group (P<0.05). However, the axon dose-dependently increased in oat-treated groups (100, 200, and 400 mg/kg), compared to that in the control group after 4 weeks (P<0.05). These results suggest that oat extract has positive effects on sciatic nerve repair in rats.
- انتشار مقاله: 16-10-1397
- نویسندگان: Z. Darzian Rostami,A. Asghari,A. Jahandideh,P. Mortazavi,A. Akbarzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Rat,Nanofibres,eugenol,Zinc oxide,skin,WOUND HEALING
- چکیده:
- چکیده انگلیسی: In order to evaluate the healing effect of eugenol and other nanofibers, 100 male Wistar rats (200±10 g) were used with 14-15 weeks of age in this study. All of the male rats were transferred in the standard cages under controlled exposure conditions in a 12:12 h light/dark cycle with a constant temperature about 22±2 oC. In addition, the male rats were fed with pellets. Firstly, anesthesia process was performed by 2% xylazine hydrochloride (10mg/Kg/IP) and 10% ketamine hydrochloride (100mg/Kg/IP), and then the rats were placed on the operating table. Then the dorsal surfaces of the rats’ skin to ileum were scrubbed and prepared as the next step. A circular wound (with a 7 mm diameter) was created by a 7 mm sterile biopsy punch. All 100 rats were divided into four groups (n=25) randomly named as control, nano zinc oxide (ZnO), eugenol nanofibers, and polycaprolactone groups. After that, they were divided into five groups regarding the wound closure rate in days 3, 5, 7, 14, and 21. Then, the wound dressings were placed on the wounds and renewed every 24 h. At the end of days 3, 5, 7, 14, and 21, the relevant tests, such as histopathology, were conducted by removing the tissue volume using a biopsy punch, and then decapitation process was performed on the rats. It was obvious that eugenol nanofiber showed the best granulation tissue by the production of collagen. Further studies are being performed on wound healing by eugenol nanofiber.
- انتشار مقاله: 26-10-1396
- نویسندگان: M. A. Ashjazadeh,A. Jahandideh,G. Abedi,A. Akbarzadeh,S. Hesaraki
- مشاهده