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211.
In this work, variation of piezoelectric strain coe?cient and permittivity with change in electric field is included in constitutive equations of piezoelectricity and used for developing finite element model of a plate instrumented with piezoelectric patches. Simulation results show that nodal displacement response and sensor voltage is less controlled if variation of piezoelectric strain coe?cient and permittivity with change in electric field is not included in finite element modelling as compared to the case in which these variations are included in finite element modeling. An experiment is performed so as to validate simulation results. 相似文献
212.
Transport in Porous Media - A large number of studies were carried out in the past to analyze the significance of colloids and microbes in remediating groundwater aquifers contaminated with... 相似文献
213.
214.
Santosh Kumar Kudtarkar Renu Dhadwal 《Journal of magnetism and magnetic materials》2010,322(16):2287-2292
We determine the induced voltage generated by spatial and temporal magnetisation textures (inhomogeneities) in metallic ferromagnets due to the spin diffusion of non-equilibrium electrons. Using time dependent semi-classical theory as formulated in Zhang and Li [1] and the drift-diffusion model of transport it is shown that the voltage generated depends critically on the difference in the diffusion constants of up and down spins. Including spin relaxation results in a crucial contribution to the induced voltage. We also show that the presence of magnetisation textures results in the modification of the conductivity of the system. As an illustration, we calculate the voltage generated due to a time dependent field driven helimagnet by solving the Landau-Lifshitz equation with Gilbert damping and explicitly calculate the dependence on the relaxation and damping parameters. 相似文献
215.
Garima Agarwal Vaibhav Kulshrestha Renu Dhunna D. Kabiraj Shikha Verma I. P. Jain 《Applied Physics A: Materials Science & Processing》2010,99(4):879-888
Swift heavy ion (SHI) beam induced irradiation is an established technique for investigating structural modifications in thin films depending
on the S
e sensitivity of material. Intermixing due to 120 MeV Au ion irradiation at different fluences from 1012 to 1014 ions/cm2 has been reported as a function of ion fluence in a-Si/Zr/a-Si thin films on Si substrate. The samples are characterized
before (pristine) and after irradiation using Grazing Incident X-ray Diffraction (GIXRD) and Rutherford Backscattering Spectroscopy
(RBS), which confirm the formation of ZrSi at thin film interface. It is suggested that mixing is mainly due to electronic
energy loss since the energy transferred from high energy ions seems to create a transient molten zone along the ion track.
It is found that the interface mixing increases linearly with the increase in ion fluence. The mixing effect explained in
the framework of Thermal spike model. The irradiation effect on the surface roughness of the system is measured using Atomic
Force Microscopy (AFM) technique. The current conduction mechanism and Schottky barrier height are also calculated by taking
I–V curves across the Metal/Si junction. 相似文献
216.
Nidhi Renu Gupta Tanu Sharma Sanjeev Aggarwal S. Kumar 《Indian Journal of Physics》2009,83(7):921-926
The samples of CR-39 polymer (TASTRAK, Bristol, England) were annealled thermally at various temperatures ranging from 100°C
to 180°C for 1 hour, in air. FTIR spectroscopy reveals the structural degradation of CR-39 polymer due to thermal annealing
above its glass transition temperature. Optical band gap of pristine and thermally annealed samples has been determined using
UV-Visible absorption spectra. It has been observed that the optical band gap decreases continuously as a result of annealing.
相似文献
217.
This paper provides the detailed simulation analysis of Filter Bank Multicarrier Cognitive Radio for doing tradeoff between the parameters of cognitive radio for achieving optimum performance. An attempt for tradeoff between different transmission-radio environment parameters has been done as this leads to an increase in spectrum efficiency by decreasing the spectral leakage which provides optimal performance. The optimization-tradeoff between different radio environment parameters is necessary for prediction and planning of future wireless communication systems. Transmission, reception and radio environment parameters play a key role in the performance enhancement of FBMC cognitive radio. 相似文献
218.
Sham Ravindranath Shi-Qing Wang M. Olechnowicz V. S. Chavan R. P. Quirk 《Rheologica Acta》2011,50(2):97-105
This work aims to elucidate how molecular parameters dictate the occurrence of inhomogeneous cohesive failure during step
strain and large amplitude oscillatory shear (LAOS) respectively in entangled polymer mixtures. Based on three well-entangled
polybutadiene (PB) mixtures, we perform simultaneous rheometric and particle-tracking velocimetric (PTV) measurements to illustrate
how the slip length controls the degree of shear banding. Specifically, the PB mixtures were prepared using the same parent
polymer (M
w ∼ 106 g/mol) at 10 wt.% concentration in respective polybutadiene solvents (PBS) of three different molecular weights 1.5, 10,
and 46 kg/mol. After step strain, the entangled PB mixture with PBS-1.5 K displayed interfacial failure whereas the PB mixture
with PBS-10 K showed bulk failure, demonstrating the effectiveness of our strategy to suppress wall slip by controlling PBS’
molecular weight. Remarkably, the PBS-46K actually allows the elastic yielding to occur homogeneously so that no appreciable
macroscopic motions were observed upon shear cessation. PBS is found to play a similar role in LAOS of these three PB mixtures.
Finally, we demonstrate that in case of the slip-prone mixture based on PBS-1.5 K the interfacial failure could be drastically
reduced by use of shearing plates with considerable surface roughness. 相似文献
219.
220.
Gunasekar Ramachandran Munusamy Sathishkumar Ravindranath S. Rathore Periyasamy Giridharan 《合成通讯》2013,43(19):2227-2239
A simple and efficient approach was developed to synthesize symmetrical/unsymmetrical bis[1,3]oxazines using ammonium acetate with controllable substitution patterns in a one-pot fashion. In a representative crystal structure, the [1,3]oxazine ring is in a distorted semichair conformation with C2-carbon and nitrogen atoms residing above and below the naphthalene plane, leading to strain in the ring that allows ring-opening polymerization to take place. A few of the derivatives were found to possess anticancer activity. This current modest protocol affords numerous advantages such as mild reaction condition, shorter reaction time, operational simplicity, and excellent yield. 相似文献