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排序方式: 共有231条查询结果,搜索用时 140 毫秒
1.
Bushra Bashir Muhammad Usman Khalid Muhammad Aadil Sonia Zulfiqar Muhammad Farooq Warsi Philips O. Agboola Imran Shakir 《Ceramics International》2021,47(3):3603-3613
NiO nanostructure was synthesized using a simple co-precipitation method and was embedded on reduced graphene oxide surface via ultrasonication. Structural investigations were made through X-ray diffraction (XRD) and functional groups were confirmed by Fourier transform infrared spectroscopy (FTIR). XRD analysis revealed the grain size reduction with doping. Fourier transform infrared spectroscopy confirmed the presence of metal-oxygen bond in pristine and doped NiO nanostructure as well as the presence of carbon containing groups. Scanning electron microscopy (SEM) indicated that the particle size decreased when NiO nanostructure was doped with copper. BET surface area was found to increase almost up to 43 m2/g for Cu doped NiO nanostructure/rGO composite. Current-voltage measurements were performed using two probe method. UV–Visible spectroscopic profiles showed the blue and red shift for Cu doped NiO nanostructure and Cu doped NiO Nanostructure/rGO composite respectively. Rate constant for Cu doped NiO nanostructure/rGO composite found to increase 4.4 times than pristine NiO nanostructure. 相似文献
2.
Nisar Ahmad Shah Syed Zaffer Iqbal Basharat Parveen 《AEUE-International Journal of Electronics and Communications》2005,59(7):410-412
A new topology simultaneously implementing lowpass (LP) and bandpass (BP) transadmittance filtering signals using a single operational amplifier (OA), one capacitor, and two resistors is presented. The input impedance is very high which is essential for cascading without employment of buffers. The circuit uses absolute minimum number of active and passive components. The filter employs pole-model of OA and as such has acquired suitability for extended frequency operation. The circuit permits separate adjustment of natural frequency (ω0) and quality factor (Q) in an orthogonal manner. The circuit has low sensitivity figures unlike the reported single amplifier biquads. The PSPICE simulation results are included. 相似文献
3.
The present article is concerned with the investigation of disturbances in a homogeneous transversely isotropic thermoelastic rotating medium with two temperatures, in the presence of the combined effects of Hall currents and magnetic field. The formulation is applied to the thermoelasticity theories developed by Green-Naghdi theories of type-II and type-III. Laplace and Fourier transform techniques are applied to solve the problem. The analytical expressions of displacements, stress components, temperature change, and current density components are obtained in the transformed domain. A numerical inversion technique has been applied to obtain the results in the physical domain. Numerical simulated results are depicted graphically to show the effect of Hall current and two temperatures on resulting quantities. Some special cases are also deduced from the present investigation. 相似文献
4.
In this paper, we have successfully presented a fuzzy Petri net (FPN) model to design the genetic regulatory network. Based on the FPN model, an efficient algorithm is proposed to automatically reason about imprecise and fuzzy information. By using the reasoning algorithm for the FPN, we present an alternative approach that is more promising than the fuzzy logic. The proposed FPN approach offers more flexible reasoning capability because it is able to obtain results with fuzzy intervals rather than point values. In this paper, a novel model with a new concept of hidden fuzzy transition (HFT) to design the genetic regulatory network is developed. We have built the FPN model and classified the input data in terms of time point and obtained the output data, so the system can be viewed as the two-input and one output system. This method eliminates possible false predictions from the classical fuzzy model thereby allowing a wider search space for inferring regulatory relationship. The experimental results show the proposed approach is feasible and acceptable to design the genetic regulatory network and investigate the dynamical behaviors of gene network. 相似文献
5.
Exploring a virtual model under simulated environments is the best way to learn about a real system. This is particularly true in robotics where it is quite expensive to provide the system to each individual. The interdisciplinary area of robotics is being studied commonly in various fields like electrical, computer, mechanical engineering, nanotechnology, etc. A virtual robot system can help one fully understand the controls and working of a robot. The system may also be helpful to design the path and plan the trajectory of a robot in an industrial environment or other robotics application. Virtual model of RV-M1 robot has been developed in the MATLAB environment. The virtual system performs forward kinematics and inverse kinematics in addition to providing a simulation of the robot teachbox. 相似文献
6.
7.
Bushra Bashir Abdur Rahman Humera Sabeeh Muhammad Azhar Khan Mohamed F. Aly Aboud Muhammad Farooq Warsi Imran Shakir Philips Olaleye Agboola Muhammad Shahid 《Ceramics International》2019,45(6):6759-6766
Nickel ferrites with high theoretical capacitance value as compared to the other metal oxides have been applied as electrode material for energy storage devices i.e. batteries and supercapacitors. High tendency towards aggregation and less specific surface area make the metal oxides poor candidate for electrochemical applications. Therefore, the improvements in the electrochemical properties of nickel ferrites (NiFe2O4) are required. Here, we report the synthesis of graphene nano-sheets decorated with spherical copper substituted nickel ferrite nanoparticles for supercapacitors electrode fabrication. The copper substituted and unsubstituted NiFe2O4 nanoparticles were prepared via wet chemical co-precipitation route. Reduced graphene oxide (rGO) was prepared via well-known Hummer's method. After structural characterization of both ferrite (Ni1-xCuxFe2O4) nanoparticles and rGO, the ferrite particles were decorated onto the graphene sheets to obtain Ni1-xCuxFe2O4@rGO nanocomposites. The confirmation of preparation of these nanocomposites was confirmed by scanning electron microscopy (SEM). The electrochemical measurements of nanoparticles and their nanocomposites (Ni0.9Cu0.1Fe2O4@rGO) confirmed that the nanocomposites due to highly conductive nature and relatively high surface area showed better capacitive behavior as compared to bare nanoparticles. This enhanced electrochemical energy storage properties of nanocomposites were attributed to the graphene and also supported by electrical (I-V) measurements. The cyclic stability experiments results showed ~65% capacitance retention after 1000 cycles. However this retention was enhanced from 65% to 75% for the copper substituted nanoparticles (Ni0.9Cu0.1Fe2O4) and 65–85% for graphene based composites. All this data suggest that these nanoparticles and their composites can be utilized for supercapacitors electrodes fabrication. 相似文献
8.
9.
Randhir Singh Ajay Kumar Parveen Kumar Lehana 《International Journal of Speech Technology》2017,20(3):659-672
Alexandrine and Indian Ringneck parrots are known for imitating the voice of other animals. The objective of this paper is to estimate the spectral limits of the imitated sounds produced by parrots and quantify the quality. The investigations showed that 500–3000 Hz spectral band is adequate for retaining the important perceptual information in the phrases uttered by human speakers and imitated by parrots. Investigations confirmed that the Indian Ringneck parrots are capable of following the formant structure and pitch contour of the phrases uttered by the human subjects. The dynamic range of the pitch of Indian Ringneck parrots was observed as higher than that of the human subjects. A rise of about 1000 Hz in the formant F1 of the parrots was observed, indicating the tongue height small and beak opening, relatively large, as compared to that of human subjects. The quality of some of the synthesized and processed phrases was found slightly better as compared to that of the original phrases because of the inherent enhancement capability of the Harmonic plus noise model (HNM). The average Mean opinion score (MOS) score of the Indian Ringnech parrots for the original, synthesized, and processed phrases was observed as 2.65, 2.59, and 2.77, respectively. The investigations may be beneficial for studying the behavior of endangered birds, defense related activities, safeguarding the crashes with aero planes, and safeguard of the birds from wind power generator etc. 相似文献
10.
Saleem Khan Sandeep Arya Parveen Lehana Suresh Kumar 《Bulletin of Materials Science》2014,37(4):889-893
The special behaviour of nanowires with respect to electrical conductivity makes them suitable for sensing application. In this paper, we present a copper-ferrous (CuFe) nanowires based sensor for detection of chemicals. CuFe nanowires were synthesized by template-assisted electrochemical method. By optimizing the deposition parameters, continuous nanowires on a copper substrate were synthesized. The morphological and structural studies of the synthesized CuFe nanowires were carried out using scanning electron microscope (SEM) and X-ray diffraction (XRD). Substrates containing CuFe nanowires were moulded to form a capacitor. Different chemicals were used as dielectric in the capacitor which showed that the capacitance was a nonlinear function of the dielectric constant of fluid unlike the linear relation shown by conventional capacitors. This unique property of the nanowires based capacitors may be utilized for developing fluid sensors with improved sensitivity. 相似文献