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21.
The electrical properties of double perovskite Ho2NiTiO6 (HNT) are investigated by impedance spectroscopy in the temperature range 30–420 °C and frequency range 100 Hz to 1 MHz.
The X-ray diffraction analysis reveals that the compound crystallizes in monoclinic phase. The imaginary part of impedance
(Z″) as a function of frequency shows Debye type relaxation. The frequency dependence of Z″ peak is found to obey an Arrhenius law with an activation energy of 0.129 eV. Impedance data presented in the Nyquist plot
(Z″ vs. Z′) are used to identify an equivalent circuit and to know the bulk and interface contributions. The complex impedance analysis
of HNT exhibits the appearance of both the grain and grain-boundary contribution. The results of bulk ac conductivity as a
function of temperature and frequency are presented. The activation energy (0.129 eV), calculated from the slope of log τ
versus 103/T plot, is found to be the nearly same as calculated (0.130 eV) from dc conductivity. The frequency dependent conductivity
spectra obey the power law. 相似文献
22.
Abhay Kumar Singh Mukesh K. Mahato Babita Neogi K. K. Singh 《Mine Water and the Environment》2010,29(4):248-262
In a qualitative assessment of mine water from the Raniganj coalfield, 77 mine water samples were analyzed to assess water
quality and suitability for domestic, industrial, and irrigation uses. The pH of the mine water ranged from 6.5 to 8.8. Total
dissolved solids (TDS) ranged from 171 to 1,626 mg L−1; spatial differences between the TDS values reflect variations in lithology, activities, and prevailing hydrological regime.
The anion chemistry was dominated by HCO3
− and SO4
2−. On average, Cl− contributes 10 and 19% of the total anionic balance, respectively, in the Barakar and Raniganj Formation mine water. F− and NO3
− contribute <2% to the total anions. The cation chemistry is dominated by Mg2+ and Ca2+ in the mine water of the Barakar Formation and Na+ in the Raniganj Formation mines. Much of the mine water, especially of the Barakar Formation area, has high TDS, total hardness,
and SO4 concentrations. Concentrations of some trace metals (i.e. Fe, Cr, Ni) were found to be above the levels recommended for drinking
water. However, the mine water can be used for irrigation, except at some sites, especially in the Raniganj Formation area,
where high salinity, sodium adsorption ratio, %Na, residual sodium carbonate, and excess Mg restrict its suitability for agricultural
uses. 相似文献
23.
Ashiq Mohammad Dhekne Pushkar Hamada Atef Saad Sahu Puspendu Mahato B. Minz R. K. Ghosh Chowdhury Sandip Pentti Karjalainen L. 《Metallurgical and Materials Transactions A》2017,48(10):4842-4856
Metallurgical and Materials Transactions A - The evolution of microstructure and texture of a two-phase austenite-ferrite twinning-induced plasticity steel during cold rolling was investigated and... 相似文献
24.
Aeroelastic performances of smart composite plates under aerodynamic loads are investigated in hygro-thermal environment. The active fiber composite (AFC) which is more effective and adaptive than conventional monolithic piezoelectric material is used in the present analysis to control the undesirable response due to hygrothermal effect. In the presence of hygrothermal load the composite structure becomes weak. But the structure can regain its stiffness in hygro-thermal environment when the AFC layer is activated with the help of applied voltage. The AFC is also effective to enhance the flutter boundary of present aeroelastic structure in hygro-thermal environment. 相似文献
25.
Journal of Materials Science - We report upon synthesis of stable chains of magnetically aligned zero-valent α-Fe nanoparticles and investigation of their magnetization reversal mechanism. The... 相似文献
26.
27.
High‐temperature tensile behavior at different crosshead speeds during loading of glass fiber‐reinforced polymer composites
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The present study evaluates on the static tensile behavior of glass fiber reinforced polymer (GFRP) composites at 50% and 70% volume fractions of reinforcement tested at room (25 °C), 70 °C, 90 °C, and 110 °C temperatures with 1, 10, 100, 500, and 1000 mm/min crosshead speeds to investigate the impact of high temperature on the mechanical properties and different dominating failures modes. The experimental results reveal that with increase in crosshead speeds the tensile strength of the composite is increasing. The effect of crosshead speeds and temperature with changing fiber volume fractions affects the GFRP composite. Although both the composite systems are found to be crosshead speed sensitive. Crosshead speed sensitivity seems to be more unpredictable at high temperature and at high crosshead speed. Furthermore, it appears to be more unprecedented nature of fluctuation with high fiber volume fraction. The crucial parameters required during the materials designing in various structural components were evaluated and modelled with the help of Weibull constitutive model. The fractography analyses were done to identify the various dominating failure modes in the GFRP composite. There was no significant change found in the glass transition temperatures (Tg) of both the composite system when exposed to different temperature environments. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44715. 相似文献
28.
Microsystem Technologies - EEG signals are non-stationary, complex and non-linear signals. During major depressive disorder (MDD) or depression, any deterioration in the brain function is reflected... 相似文献
29.
30.
P. Chakraborty S.S. Mahato M.K. Bera S.K. Samanta C.K. Maiti 《Microelectronic Engineering》2009,86(3):299-302
Potential of high-k dielectric films for future scaled charge storage non-volatile memory (NVM) device applications is discussed. To overcome the problems of charge loss encountered in conventional flash memories with silicon-nitride (Si3N4) films and polysilicon-oxide-nitride-oxide-silicon (SONOS) and nonuniformity issues in nanocrystal memories (NC), such as Si, Ge and metal, it is shown that the use of high-k dielectrics allows more aggressive scaling of the tunnel dielectric, smaller operating voltage, better endurance, and faster program/erase speeds. Charge-trapping characteristics of high-k AlN films with SiO2 as a blocking oxide in p-Si/SiO2/AlN/SiO2/poly-silicon (SOHOS) memory structures have been investigated in detail. The experimental results of program/erase characteristics obtained as the functions of gate bias voltage and pulse width are presented. 相似文献