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131.
Amir Amirabadi Mojtaba Chehelcheraghi Mahmoud Kamarei 《Circuits, Systems, and Signal Processing》2011,30(4):721-739
A third-order intermodulation cancelation technique using a non-linear feedback is proposed to design a low-power low-distortion
mixer in a 65 nm standard CMOS technology. The IM3 cancelation is achieved by estimating distorting error at a non-linear
feedback element and subtracting it from the input. The linearization technique is utilized in the input trans-conductance
of the mixer. The circuit functionality is analyzed using Volterra series. The covering frequency range of the mixer is 800 MHz
to 5 GHz. The technique increases the input-referred third-order intercept point (IIP3) and input 1 dB compression point to
+16.4 dBm and −1.87 dBm, respectively. It obtains a gain of 9 dB and an input-referred noise of 1.84 nV/?{}/\sqrt{}Hz while consumes 8.75 mA from 1.2 V supply. The layout of the mixer occupies 0.315 mm × 0.296 mm of silicon area. 相似文献
132.
Seyyed Mojtaba Mousavi Seyyed Alireza Hashemi Sonia Bahrani Khadije Yousefi Gity Behbudi Aziz Babapoor Navid Omidifar Chin Wei Lai Ahmad Gholami Wei-Hung Chiang 《International journal of molecular sciences》2021,22(13)
In this review, the unique properties of intrinsically conducting polymer (ICP) in biomedical engineering fields are summarized. Polythiophene and its valuable derivatives are known as potent materials that can broadly be applied in biosensors, DNA, and gene delivery applications. Moreover, this material plays a basic role in curing and promoting anti-HIV drugs. Some of the thiophene’s derivatives were chosen for different experiments and investigations to study their behavior and effects while binding with different materials and establishing new compounds. Many methods were considered for electrode coating and the conversion of thiophene to different monomers to improve their functions and to use them for a new generation of novel medical usages. It is believed that polythiophenes and their derivatives can be used in the future as a substitute for many old-fashioned ways of creating chemical biosensors polymeric materials and also drugs with lower side effects yet having a more effective response. It can be noted that syncing biochemistry with biomedical engineering will lead to a new generation of science, especially one that involves high-efficiency polymers. Therefore, since polythiophene can be customized with many derivatives, some of the novel combinations are covered in this review. 相似文献
133.
Mojtaba Hossienifard Lida Hashemi Vahid Amani Khadijeh Kalateh Ali Morsali 《Journal of Inorganic and Organometallic Polymers and Materials》2011,21(3):527-533
A new nano-sized Zn(II) complex, [Zn(5,5′-dtbu-2,2′-bipy)Cl2]
n
(1) was synthesized and its structure determined by X-ray crystallography. The new nano-sized complex was prepared at oleic
acid as a surfactant at 280 °C and characterized by scanning electron microscopy, elemental analyses and IR spectroscopy.
The ZnO nano-particles were synthesized from thermolysis of nano-compound 1 at 600 °C and similar compound, [Zn(5,5′-dimethyl-2,2′-bipy)Cl2]
n
(2), at two different methods. SEM images show the average size of ZnO nano-particles are 78 and 50 nm for the compounds 1 and 2, respectively. 相似文献
134.
A three‐dimensional simulation of the Underground coal gasification (UCG) process is studied in terms of the heat and mass transport phenomena and chemical kinetics in a coal seam during coal combustion by applying the controlled retracting injection point technique. The STARS module of the Computer Modelling Group software is used in this study. The gas species flow rate, cavity shapes, and temperature profile in the coal seam during gasification are investigated. The main motivation behind this study is to provide a simulation methodology by using a comprehensive porous media flow approach to understand the critical aspects of the UCG process. 相似文献
135.
Mojtaba Shamsipur Mostafa Najafi Mohammad-Reza Milani Hosseini 《Journal of Applied Electrochemistry》2013,43(10):1027-1033
Electrocatalytic oxidation of methanol and some other primary alcohols on a glassy carbon electrode modified with multi-walled carbon nanotubes and nano-sized nickel oxide (GCE/MWNT/NiO) was investigated by cyclic voltammetry and chronoamperometry in alkaline medium. The results were compared with those obtained on a nickel oxide-modified glassy carbon electrode (GCE/NiO). Both the electrodes were conditioned by potential cycling in the range of 0.1–0.6 V versus Ag/AgCl in a 0.10 M NaOH solution. The effects of various parameters such as scan rate, alcohol concentration, thickness of NiO film, and real surface area of the modified electrodes were also investigated and compared. It was found that the GCE/MWNT/NiO-modified electrode possesses an improved electrochemical behavior over the GC/NiO-modified electrode for methanol oxidation. 相似文献
136.
Mojtaba Delfanian Reza Esmaeilzadeh Kenari Mohammad Ali Sahari 《International Journal of Food Properties》2013,16(12):2813-2824
The antioxidation activities of Eriobotrya japonica (Lindl.) fruit peel and pulp extracts were determined using DPPH, β-carotene, and Rancimat methods. Results showed that ethanol-water extract of peel and ethanol extract of pulp had the highest antioxidant activity. Protective effects of extracts in stabilization of soybean oil were tested and compared to tert-butyl hydroquinone by measuring peroxide values, free fatty acids, thiobarbituric acid, oxidative stability, and conjugated dienes and trienes values during storage (65 days at 25°C). Results showed that the ethanol-water extract of peel at 400 ppm exhibited stronger antioxidant activity, but the highest effect was observed in tert-butyl hydroquinone. 相似文献
137.
Firouz Matloubi Moghaddam Hassan Zali Boeini Mojtaba Bagheri Peter Rüedi Anthony Linden 《Journal of Sulfur Chemistry》2013,34(3):245-250
A novel, efficient, and very mild one-pot synthesis of methyl 2-[(Z)-4-aryl-5-morpholino-3-oxo-2,3-dihydrothiophen-2-ylidene]acetate derivatives under kinetic control has been developed. The title compounds were prepared by the reaction of thioacetomorpholides with dimethyl acetylene-dicarboxylate (DMAD) in the presence of K2CO3 in a non-polar solvent with excellent yields. 相似文献
138.
Mojtaba Beheshti Mohammad Javad Omidi Ali Mohammad Doost-Hoseini 《Wireless Personal Communications》2013,71(2):1193-1215
Shallow underwater acoustic (UWA) channel exhibits rapid temporal variations, extensive multipath spreads, and severe frequency-dependent attenuations. So, high data rate communication with high spectral efficiency in this challenging medium requires efficient system design. Multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO–OFDM) is a promising solution for reliable transmission over highly dispersive channels. In this paper, we study the equalization of shallow UWA channels when a MIMO–OFDM transmission scheme is used. We address simultaneously the long multipath spread and rapid temporal variations of the channel. These features lead to interblock interference (IBI) along with intercarrier interference (ICI), thereby degrading the system performance. We describe the underwater channel using a general basis expansion model (BEM), and propose time-domain block equalization techniques to jointly eliminate the IBI and ICI. The block equalizers are derived based on minimum mean-square error and zero-forcing criteria. We also develop a novel approach to design two time-domain per-tone equalizers, which minimize bit error rate or mean-square error in each subcarrier. We simulate a typical shallow UWA channel to demonstrate the desirable performance of the proposed equalization techniques in Rayleigh and Rician fading channels. 相似文献
139.
A novel methodology for the order‐reduction of parabolic partial differential equation (PDE) systems with time‐varying domain is explored. In this method, a mapping functional is obtained, which relates the time‐evolution of the solution of a parabolic PDE with time‐varying domain to a fixed reference domain, while preserving space invariant properties of the initial solution ensemble. Subsequently, the Karhunen–Loève decomposition is applied to the solution ensemble on fixed spatial domain resulting in a set of optimal eigenfunctions. Further, the low dimensional set of empirical eigenfunctions is mapped on the original time‐varying domain by an appropriate mapping, resulting in the basis for the construction of the reduced‐order model of the parabolic PDE system with time‐varying domain. This methodology is used in three representative cases, one‐ and two‐dimensional (1‐D and 2‐D) models of nonlinear reaction‐diffusion systems with analytically defined domain evolutions, and the 2‐D model of the Czochralski crystal growth process with nontrivial geometry. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4142–4150, 2013 相似文献
140.
In this study electrochemical corrosion behavior of Zr41.2Ti13.8Ni10Cu12.5Be22.5 bulk metallic glass (BMG) in various aqueous solutions (3.5% NaCl, 1 N HNO3, H2SO4 and HCl) in order to compare with 316L stainless steel were thoroughly investigated. Scanning electron microscopy (SEM) was used to evaluate the influence of corrosion on the surface topography in immersion specimens to examine where the corrosion pits initiated. Corrosion rate of Zr41.2Ti13.8Ni10Cu12.5Be22.5 BMG in 3.5% NaCl solution was ∼0.6 mpy and its excellent corrosion resistance can be concluded. Polarization and SEM results also vouched a remarkable corrosion resistance of Zr41.2Ti13.8Ni10Cu12.5Be22.5 BMG in 3.5% NaCl aqueous solution in comparison with 316L stainless steel. 相似文献