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71.
Rezaei Sadr Nahid Bahrdo Tarokh Taghizadeh Rahim 《Clean Technologies and Environmental Policy》2022,24(5):1521-1534
Clean Technologies and Environmental Policy - The Paris agreement is a legally binding international treaty on climate change. This study examines the Paris agreement and other explanatory... 相似文献
72.
Wireless Networks - In this paper, a Mercedes-Benz logo antenna with a metal plate located at an optimized distance from the proposed antenna is introduced as a wearable antenna to operate in the... 相似文献
73.
Amin Heidari Mostafa Rezaei Hasan Keshavarz-Mirzamohamadi Elchin Jafariyeh-Yazdi 《Polymer-Plastics Technology and Engineering》2018,57(13):1313-1324
We address the immobilization of single-site catalyst on the graphite oxide (GO) surface using methylaluminoxane. Ethylene polymerization was performed using the immobilized catalyst and the nanocomposite of ultrahigh molecular weight polyethylene (UHMWPE)/GO with less entanglement density was obtained. It was observed that the drawability, mechanical and thermal properties of the produced polymer significantly are affected by the anchoring of polymer chains to the GO nanosheets. The orientation and location of crystalline lamellae and nanosheets were verified by microscopic techniques. Besides, X-ray analysis demonstrated the dispersion of GO within the UHMWPE phase and crystallinity of UHMWPE/GO nanocomposites enhanced during drawing process. 相似文献
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76.
Mostafa Rezaei Azadeh Shirzad Nadereh Golshan Ebrahimi Marianna Kontopoulou 《应用聚合物科学杂志》2006,99(5):2352-2358
We performed surface modification of ultra‐high‐molecular‐weight polyethylene (UHMWPE) through chromic acid etching, with the aim of improving the performance of its composites with poly(ethylene terephthalate) (PET) fibers. In this article, we report on the morphology and physicomechanical and tribological properties of modified UHMWPE/PET composites. Composites containing chemically modified UHMWPE had higher impact properties than those based on unmodified UHMWPE because of improved interfacial bonding between the polymer matrix and the fibers and better dispersion of the fibers within the modified UHMWPE matrix. Chemical modification of UHMWPE before the introduction of PET fibers resulted in composites exhibiting improved wear resistance compared to the base material and compared to unmodified UHMWPE/PET composites. On the basis of the morphological studies of worn samples, microploughing and fatigue failure associated with microcracking were identified as the principle wear mechanisms. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
77.
H. Adibi S. M. Rezaei Ahmed A. D. Sarhan 《The International Journal of Advanced Manufacturing Technology》2013,68(1-4):473-485
Wheel surface condition plays an important role in the grinding operation. Grinding wheel loading, meaning chip accumulation in the space between grains, leads to deteriorating wheel cutting ability and causes excessive force and temperature. This paper presents an analytical model of wheel loading phenomena as a function of cutting parameters, wheel structure, and material properties. The model is based on the adhesion of workpiece material to abrasive grain surface. It is validated by experimental results from grinding nickel-based superalloy with cubic boron nitride vitrified wheel. This model considers wheel specifications including abrasive grains size and the number of cutting edges. Cutting parameters and process temperature are the other determinant factors. On the basis of this model and empirical results, the effects of the various process parameters are presented. 相似文献
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79.
Protective properties of PPy‐Au nanocomposite coatings prepared by sonoelectrochemisty and optimized by the Taguchi method 下载免费PDF全文
The polypyrrole (PPy) and polypyrrole‐Au (PPy‐Au) nanocomposite films have been sonoelectrochemically synthesized on St‐12 steel electrodes using the galvanostatic technique. Experimental design according to the Taguchi method has been applied to optimize the factors on the synthesis of PPy‐Au nanocomposite coating. Three factors were used to design an orthogonal array L9: Synthesis time (t), Current density (I), and Concentration of HAuCl4 (C). The synthesized Au nanoparticles during polymerization were characterized by Ultraviolet–visible (UV‐visible) spectroscopy. Characterization of the surfaces was done by scanning electron microscope (SEM), energy dispersive X‐ray spectrum (EDX), and atomic force microscope (AFM). The scanning electron microscopy (SEM) image of PPy shows a smooth surface while PPy‐Au nanocomposite film has a compact morphology. Moreover, energy dispersive X‐ray spectrum (EDX) is evidence for the incorporation of Au nanoparticles. The corrosion protection of coatings was investigated by open circuit potential (OCP) time trends, potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS) in a NaCl 3.5% solution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41087. 相似文献
80.
Mohammad Zareinejad Saeed Shiry Ghidary Seyed Mehdi Rezaei Amir Abdullah 《International Journal of Precision Engineering and Manufacturing》2010,11(1):55-65
Piezoelectric actuators are widely used in micro manipulation applications. However hysteresis nonlinearity limits accuracy
of these actuators. This paper presents a novel approach for utilizing a piezoelectric nano-stage as slave manipulator of
a teleoperation system. The Prandtl-Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel
out this nonlinearity. To deal with the influence of parametric uncertainties, unmodeled dynamics, and PI identification error
a perturbation term is added to the slave model and apply a sliding mode based impedance control with perturbation estimation.
The stability of the entire system is guaranteed by Llewellyn’s absolute stability criterion. Performance of the proposed
controllers is verified through experiments. 相似文献