Theoretical Analysis on Resistance-Temperature Characteristic of Ni/HCl-PANI Composites

2014 ◽  
Vol 852 ◽  
pp. 142-146 ◽  
Author(s):  
Sui Yu Qiu ◽  
Zhi Wei Yang ◽  
Hong Qiu

Ni/HCl-PANI composites were formed by depositing Ni films on HCl-doped polyaniline (HCl-PANI) substrates. A simple parallel resistor model is used to analyze the resistance-temperature (R-T) characteristic of the composite within 30-300 K. The theoretical analysis reveals that the composite exhibits a metal-semiconductor transition within a certain thickness of the Ni film or the HCl-PANI substrate. The composite shows a semiconducting behavior at temperatures over the transition temperature and a metallic conduction behavior at temperatures below the transition temperature. The transition temperature increases with increasing Ni film thickness whereas it decreases with increasing HCl-PANI substrate thickness. When the Ni film thickness exceeds its upper limit or the HCl-PANI substrate thickness is below its lower limit, the composite only shows the metallic R-T characteristic. When the HCl-PANI substrate thickness exceeds its upper limit, the composite only exhibits the semicoducting R-T characteristic.

Energy ◽  
2021 ◽  
Vol 222 ◽  
pp. 119940
Author(s):  
Qiang Li ◽  
Qian Wang ◽  
Jiansheng Zhang ◽  
Weiliang Wang ◽  
Jizhen Liu

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3631 ◽  
Author(s):  
Binjun Wang ◽  
Yunqiang Jiang ◽  
Chun Xu

Using molecular dynamics (MD) simulation, the austenitic and martensitic phase transitions in pure iron (Fe) thin films containing coherent twin boundaries (TBs) have been studied. Twelve thin films with various crystalline structures, thicknesses and TB fractions were investigated to study the roles of the free surface and TB in the phase transition. In the austenitic phase transition, the new phase nucleates mainly at the (112)bcc TB in the thicker films. The (111¯)bcc free surface only attends to the nucleation, when the film is extremely thin. The austenitic transition temperature shows weak dependence on the film thickness in thicker films, while an obvious transition temperature decrease is found in a thinner film. TB fraction has only slight influence on the austenitic temperature. In the martensitic phase transition, both the (1¯10)fcc free surface and (111)fcc TB attribute to the new body-center-cubic (bcc) phase nucleation. The martensitic transition temperature increases with decreased film thickness and TB fraction does not influent the transition temperature. In addition, the transition pathways were analyzed. The austenitic transition obeys the Burgers pathway while both the Kurdjumov–Sachs (K–S) and Nishiyama–Wassermann (N–W) relationship are observed in the martensitic phase transition. This work may help to understand the mechanism of phase transition in the Fe nanoscaled system containing a pre-existing defect.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
M. J. Plotnikov ◽  
A. V. Kulikov ◽  
V. E. Strigalev ◽  
I. K. Meshkovsky

The dependence of the dynamic range of the phase generated carrier (PGC) technique on low-pass filters passbands is investigated using a simulation model. A nonlinear character of this dependence, which could lead to dynamic range limitations or measurement uncertainty, is presented for the first time. A detailed theoretical analysis is provided to verify the simulation results and these results are consistent with performed calculations. The method for the calculation of low-pass filters passbands according to the required dynamic range upper limit is proposed.


2015 ◽  
Vol 29 (30) ◽  
pp. 1550213 ◽  
Author(s):  
Zhenhua Wu ◽  
Lei Chen ◽  
Qiang Tian

We use the fractional–dimensional approach (FDA) to study exciton binding energies in GaAs films on [Formula: see text] substrates. In this approach, the Schrödinger equation for a given anisotropic system is solved in a noninteger-dimensional space where the interactions are assumed to occur in an isotropic effective environment. The heavy-hole and light-hole exciton binding energies are calculated as functions of the film thickness and substrate thickness. The numerical results show that both the heavy-hole and light-hole exciton binding energies decrease monotonously as the film thickness increases. When the film thickness and the substrate thickness is relatively small, the change of substrate thickness has comparatively remarkable influence on both heavy-hole and light-hole exciton binding energies. As the substrate thickness increases, both the heavy-hole and light-hole exciton binding energies increase gradually. When the film thickness or the substrate thickness is relatively large, the change of substrate thickness has no significant influence on both heavy-hole and light-hole exciton binding energies.


1993 ◽  
Vol 313 ◽  
Author(s):  
Kamakhya P Ghatak ◽  
S. N. Biswas

ABSTRACTIn this paper we have studied the dia and paramagnetic susceptibilities of the holes in ultrathin films of dilute magnetic materials in the presence of a quantizing magnetic field and compared the same with that of the bulk specimens under magnetic quantization for the purpose of relative comparison. It is found, taking Hg1−xMnxTe and Cd1−xMnxSe as examples, that both the susceptibilities increase with decreasing film thickness and increasing surface concentration in oscillatory Manners. The numerical values of the susceptibilities in ultrathin films of dilute magnetic materials are greater than that of the bulk and the theoretical analysis is in agreement with the experimental data as reported elsewhere.


Author(s):  
I. A. Gibson ◽  
C. J. Hooke ◽  
J. P. O'Donoghue

This report gives details of a theoretical analysis of the lubrication of ‘O’ ring seals. Under dry contact conditions the pressure gradient at inlet to the contact zone is infinite, and an iterative solution has been developed to determine the inlet sweep of pressure under conditions of elastohydrodynamic lubrication. The exit film thickness and pressures have also been determined for conditions of variable outlet viscosity and pressure gradient. Typical results for an ‘O’ ring are given for a standard seal section.


Author(s):  
Girish Hariharan ◽  
Raghuvir Pai

A theoretical model of a four-pad bearing profile with unique adjustable or controllable features is simulated in the present study by considering load directed between the pads. Radial and tilt adjustable mechanism of the four bearing pads can effectively control and modify the rotor operating behaviour. Inward and outward motions of the bearing pads result in the generation of narrow and broader convergent regions, which directly influences the fluid film pressures. In the theoretical analysis, load-between-pad (LBP) orientations and pad adjustment configurations are taken account of by employing a modified film thickness equation. The effect of load position in influencing the steady state behaviour of the four-pad adjustable bearing under varied pad displaced conditions is analysed in this study. The outcome of the analysis highlighted the effectiveness of four-pad adjustable bearing in improving the steady state performance by operating under negative adjustment conditions and with load acting on the bearing pads.


1997 ◽  
Vol 12 (2) ◽  
pp. 541-545 ◽  
Author(s):  
T. Manabe ◽  
I. Yamaguchi ◽  
W. Kondo ◽  
S. Mizuta ◽  
T. Kumagai

La1−xSrxMnO3 (LSMO) (x = 0−0.3) films were prepared on SrTiO3(001) substrates by the dipping-pyrolysis process using metal naphthenates as starting materials. Epitaxially grown LSMO films were obtained by heat treatment at 800–1200 °C; the fluctuation of alignment of these films, evaluated by reciprocal-space mapping of asymmetric x-ray diffraction, was markedly small, as comparable to that of the substrates. The LSMO films with x = 0.1−0.3 showed metallic conduction behavior at 25–300 K, and the resistivity was as low as that of LSMO single crystals, e.g., 4.5 × 10−4 Ω · cm at 150 K for the film with x = 0.3.


1992 ◽  
Vol 114 (4) ◽  
pp. 818-822 ◽  
Author(s):  
Har Prashad

A theoretical analysis has been carried out to study the capacitive effects of roller bearings on repeated starts and stops of a machine operating under the influence of shaft voltages. The analysis gives the time required for the charge accumulation and increase of charge with time on the bearing surfaces based on bearing capacitance, resistance of film thickness and the shaft voltage. Also, it investigates the effect of gradual leakage of the accumulated charges with time as the shaft voltage falls as soon as the power supply to the machine is switched off. This paper gives an approach to determine ratio of the number of shaft revolutions required for charge accumulation and gradual discharge of the accumulated charges on the bearing surfaces depending on bearing to shaft voltage. Also, number of repeated starts and stops before initiation of craters on roller track of races are established to restrict the deterioration and damage of bearings.


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