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31.
We compare charge carrier generation/trapping related degradation in control oxide (SiO2) and HfO2/SiO2 stack of an identical equivalent-oxide-thickness (EOT) during constant gate voltage stress of n-type metal-oxide-semiconductor (nMOS) capacitors. Irrespective of these two dielectrics, the kinetics of generation of both surface states and oxide-trapped positive charges are found to be similar. Our analysis shows that the positive oxide charge buildup during CVS is due to trapping of protons by the strained SiOSi bonds in either of the devices. We demonstrate that compared to SiO2 devices, HfO2 devices with an equal EOT better perform in CMOS logic applications. On the other hand, our results indicate that the control oxide is better in charge trapping memory devices. Furthermore, the lifetime of the control oxide devices is observed longer than that of HfO2 devices at a given operating voltage. 相似文献
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33.
Anuj Deshpande Sibendu Samanta Sutharsan Govindarajan Ritwik Kumar Layek 《IET systems biology》2020,14(6):343
Dynamic biological systems can be modelled to an equivalent modular structure using Boolean networks (BNs) due to their simple construction and relative ease of integration. The chemotaxis network of the bacterium Escherichia coli (E. coli ) is one of the most investigated biological systems. In this study, the authors developed a multi‐bit Boolean approach to model the drifting behaviour of the E. coli chemotaxis system. Their approach, which is slightly different than the conventional BNs, is designed to provide finer resolution to mimic high‐level functional behaviour. Using this approach, they simulated the transient and steady‐state responses of the chemoreceptor sensory module. Furthermore, they estimated the drift velocity under conditions of the exponential nutrient gradient. Their predictions on chemotactic drifting are in good agreement with the experimental measurements under similar input conditions. Taken together, by simulating chemotactic drifting, they propose that multi‐bit Boolean methodology can be used for modelling complex biological networks. Application of the method towards designing bio‐inspired systems such as nano‐bots is discussed.Inspec keywords: cell motility, microorganisms, Boolean functionsOther keywords: multibit Boolean approach, conventional BNs, high‐level functional behaviour, steady‐state responses, chemoreceptor sensory module, drift velocity, chemotactic drifting, multibit Boolean methodology, complex biological networks, bio‐inspired systems, multibit Boolean model, chemotactic drift, dynamic biological systems, equivalent modular structure, Boolean networks, simple construction, chemotaxis network, bacterium Escherichia coli, biological systems 相似文献
34.
Keka Ojha Narayan C Pradhan Amar Nath Samanta 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(4):659-666
The alkylation of phenol with tert‐butyl alcohol was carried out in a continuous flow reactor over a catalyst synthesized from fly ash. The activity of the synthesized catalyst was compared with those of other conventional zeolite catalysts such as 13X (NaX) and Hβ. Of all the catalysts tested, zeolite Hβ showed the highest activity in phenol conversion followed by the synthesized zeolite (HZOP‐31). The activity of commercial 13X zeolite was found to be same as that of HZOP‐31. Ce‐exchanged catalyst (CeZOP‐31) showed even better performance than 13X in the alkylation of phenol. The effects of different parameters such as reactant mole ratio, temperature and space velocity on phenol conversion and tert‐butyl phenol selectivity were studied. The effect of mass transfer resistance was found to be negligible within the feed rate range and particle size range studied. The apparent activation energy for the reaction of tert‐butyl alcohol over HZOP‐31 was determined as 30.1 kJ mol?1. Copyright © 2006 Society of Chemical Industry 相似文献
35.
High dielectric constant (high-k) thin Ta/sub 2/O/sub 5/ films have been deposited on tensilely strained silicon (strained-Si) layers using a microwave plasma enhanced chemical vapour deposition technique at a low temperature. The deposited Ta/sub 2/O/sub 5/ films show good electrical properties as gate dielectrics and are suitable for microelectronic applications. The feasibility of integration of strained-Si and high-k dielectrics has been demonstrated. 相似文献
36.
Science China Technological Sciences - 相似文献
37.
Amita Verma S.B. Samanta A.K. Bakhshi S.A. Agnihotry 《Solar Energy Materials & Solar Cells》2005,88(1):47-64
Thin films of TiO2 were prepared using two different sol–gel routes. The two routes employed diethanolamine (DEA) and acetylacetone as stabilizing agents with titanium isopropoxide (Ti(OPri)4) in ethanol as the deposition solution. The densification at 500 °C achieved the nanophase TiO2 films, which were investigated by performing structural, optical and electrochemical studies. Ion storage capacity and transmission measurements showed superior response of the films derived from DEA. Between the films obtained from the two routes, the appearance of the rutile phase at lower temperature for the film synthesized using DEA was predicted on the basis of the thermal analysis of the corresponding xerogel. The nanocrystalline nature of the films was evident from the X-ray diffraction, atomic force microscopy, and scanning electron microscopy. The films deposited from both the stabilizers exhibited electrochromism in 1 M LiClO4-propylene carbonate electrolyte on cathodic polarization. 相似文献
38.
Amita Verma S.B. Samanta N.C. Mehra A.K. Bakhshi S.A. Agnihotry 《Solar Energy Materials & Solar Cells》2005,86(1):85-103
Mixed CeO2–TiO2 coatings synthesized by sol–gel spin coating process using mixed organic–inorganic Ti(OC3H7)4 and CeCl3·7H2O precursors with different Ce/Ti mole ratios were investigated by a wide range of characterization techniques. The attempts were directed towards achieving coatings with high transparency in the visible region and good electrochemical properties. Elucidation of the structural and optical features of the films yielded information on the aspects relevant to their usage in transmissive electrochromic devices. The films have been found to exhibit properties for counter electrode in electrochromic smart windows in which they are able to retain their transparency under charge insertion, high enough for practical uses. The high optical modulation and fastest switching for WO3 film in the device configuration with the Ce/Ti (1:1) film is interpreted in terms of conducive microstructural changes induced by addition of TiO2 in an amount equivalent to CeO2. 相似文献
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40.
Interleukin 8 (IL-8), a neurophil-activating and chemotactic cytokine, is known to play a key role in the pathogenesis of a large number of neutrophil-driven inflammatory diseases. Although the cytokine is rapidly internalized at 37 degrees C with its receptors, there was no direct evidence for the ligand-induced endocytosis of the receptor or that of the interaction of receptor ligand complex at 37 degrees C. As a result, our understanding about the regulation of Il-8 induced biological response is very limited. In the present study, using FITC-IL-8 conjugate as a probe, we have demonstrated the time- and temperature-dependent endocytosis of IL-8 under fluorescent microscope. We have also shown that the bright fluorescent light on the surface of neutrophils gradually disappears and it becomes almost dark after 120 min of incubation. Monodansyl cadaverine (MDC, 900 microM), however, was found to retain the fluorescent light of FITC coupled with Il-8 on the cells. MDC and ouabain (2.5 mM) can inhibit the ligand induced endocytosis by 76% and 96%, respectively, compared to control. With respect to control, IL-8 induced biological responses e.g. IL-8 directed migration, intracellular Ca2+ release and superoxide release are significantly reduced by 77%, 94% and 76%, respectively, in presence of MDC. The study presents a direct visual evidence of the time and temperature-dependent receptor-mediated endocytosis of IL-8 which is inhibited by MDC and ouabain. This information is useful for understanding the ligand receptor interaction at 37 degrees C and may be useful for developing anti-inflammatory agents against IL-8. 相似文献