All-Solid-Thin Film Electrochromic Devices Consisting of Layers ITO / NiO / ZrO2 / WO3 / ITO

We have prepared an all-solid-thin film electrochromic device (ECD), consisting of layers ITO / NiO / ZrO2 / WO3 / ITO using the PVD method. The WO3 is used as an electrochromic layer, NiO as an ion-storage layer, and ZrO2 as a solid electrolyte layer in the all-solid-thin film ECD. The optical transmittance varied between 3-59 %. The device shows the coloration and bleaching time of 120 s and 2 s, respectively, with a good memory effect and desirable cycle-life. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3101

Bias and temperature dependence of the 0.7 conductance anomaly in Quantum Point Contacts

The 0.7 (2e^2/h) conductance anomaly is studied in strongly confined, etched GaAs/GaAlAs quantum point contacts, by measuring the differential conductance as a function of source-drain and gate bias as well as a function of temperature. We investigate in detail how, for a given gate voltage, the differential conductance depends on the finite bias voltage and find a so-called self-gating effect, which we correct for. The 0.7 anomaly at zero bias is found to evolve smoothly into a conductance plateau at 0.85 (2e^2/h) at finite bias. Varying the gate voltage the transition between the 1.0 and the 0.85 (2e^2/h) plateaus occurs for definite bias voltages, which defines a gate voltage dependent energy difference $\Delta$. This energy difference is compared with the activation temperature T_a extracted from the experimentally observed activated behavior of the 0.7 anomaly at low bias. We find \Delta = k_B T_a which lends support to the idea that the conductance anomaly is due to transmission through two conduction channels, of which the one with its subband edge \Delta below the chemical potential becomes thermally depopulated as the temperature is increased.Comment: 9 pages (RevTex) with 9 figures (some in low resolution

Spin-dependent thermoelectric transport coefficients in near-perfect quantum wires

Thermoelectric transport coefficients are determined for semiconductor quantum wires with weak thickness fluctuations. Such systems exhibit anomalies in conductance near 1/4 and 3/4 of 2e^2/h on the rising edge to the first conductance plateau, explained by singlet and triplet resonances of conducting electrons with a single weakly bound electron in the wire [T. Rejec, A. Ramsak, and J.H. Jefferson, Phys. Rev. B 62, 12985 (2000)]. We extend this work to study the Seebeck thermopower coefficient and linear thermal conductance within the framework of the Landauer-Buettiker formalism, which also exhibit anomalous structures. These features are generic and robust, surviving to temperatures of a few degrees. It is shown quantitatively how at elevated temperatures thermal conductance progressively deviates from the Wiedemann-Franz law.Comment: To appear in Phys. Rev. B 2002; 3 figure

Conductance anomalies and the extended Anderson model for nearly perfect quantum wires

Anomalies near the conductance threshold of nearly perfect semiconductor quantum wires are explained in terms of singlet and triplet resonances of conduction electrons with a single weakly-bound electron in the wire. This is shown to be a universal effect for a wide range of situations in which the effective single-electron confinement is weak. The robustness of this generic behavior is investigated numerically for a wide range of shapes and sizes of cylindrical wires with a bulge. The dependence on gate voltage, source-drain voltage and magnetic field is discussed within the framework of an extended Hubbard model. This model is mapped onto an extended Anderson model, which in the limit of low temperatures is expected to lead to Kondo resonance physics and pronounced many-body effects

Effect of Substrate Temperature on the Electrochromic Properties of Nickel Oxide Thin Films by e-Beam Evaporation Method

Nickel Oxide (NiO), an anodic coloring material, is used as a counter electrode layer in Electrochromic (EC) devices in combination with Tungsten Oxide (WO3) as an EC layer. The NiO thin films were prepared on glass and indium tin oxide coated glass substrates by e-beam evaporation technique at different substrate temperatures ranging from room temperature (27 C) to 400 C. The crystallization of the film improves with increase in substrate temperature as inferred from the glancing incident X-ray diffraction measurement. The increase in substrate temperature of the films causes an increase in the transmittance. The electrochromic properties of NiO thin films were investigated in an aqueous alkaline electrolyte (1M KOH) by means of transmittance, cyclic voltammetry (CV), and chronoamperometry (CA) measurements. It is found that films prepared at lower substrate temperature, up to 100 C, have better EC properties. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3532

Iron enhances hepatic fibrogenesis and activates TGF-β signaling in murine hepatic stellate cells

Introduction Although excess iron induces oxidative stress in the liver, it is unclear whether it directly activates the hepatic stellate cells (HSC). Methods We evaluated effects of excess iron on fibrogenesis and TGF-β signaling in murine HSC. Cells were treated with holotransferrin (0.005–5 g/L) for 24 h, with or without the iron chelator deferoxamine (10 µM). Gene expressions (α-SMA, Col1-α1, Serpine-1, TGF-β, Hif1-α, Tfrc and Slc40a1) were analyzed by qRT-PCR, while TfR1, ferroportin, ferritin, vimentin, collagen, TGF-β RII and phospho-Smad2 proteins were evaluated by immunofluorescence, western blot and ELISA. Results HSC express the iron-uptake protein TfR1, and the iron-export protein ferroportin. Holotransferrin up-regulated TfR1 expression by 1.8-fold (p<0.03) and ferritin accumulation (iron storage) by 2-fold (p<0.01), and activated HSC with 2-fold elevations (p<0.03) in α-SMA mRNA and collagen secretion, and a 1.6-fold increase (p<0.01) in vimentin protein. Moreover, holotransferrin activated the TGF-β pathway with TGF-β mRNA elevated 1.6-fold (p=0.05), and protein levels of TGF-β RII and phospho-Smad2 increased by 1.8-fold (p<0.01) and 1.6-fold (p<0.01), respectively. By contrast, iron chelation decreased ferritin levels by 30% (p<0.03), inhibited collagen secretion by 60% (p<0.01), repressed fibrogenic genes α-SMA (0.2-fold; p<0.05) and TGF-β (0.4-fold; p<0.01), and reduced levels of TGF-β RII and phospho-Smad2 proteins. Conclusion HSC express iron transport proteins. Holotransferrin (iron) activates HSC fibrogenesis and the TGF-β pathway, while iron depletion by chelation reverses this, suggesting that this could be a useful adjunct therapy for patients with fibrosis. Further studies in primary human HSC and animal models are necessary to confirm this

Physical Model for Plaque Action in the Tooth-Plaque-Saliva System

A physical model describing the interrelationships of demineralization, remineralization, plaque thickness, glucose levels, and plaque enzymatic activity was presented. Selection of constants and variations of the parameters were kept in the range of possible in vivo situations. The results of calculations were discussed and correlated with the results of in vivo studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66483/2/10.1177_00220345700490013001.pd

Horseplay, care and hands on hard work: gendered strategies of a project manager on a construction site

The discourse of managerial expertise favours rational analysis and masculine ideals but contemporary management literature also recognises the value of well-being and employee voice in the workplace. Drawing upon narrative analysis of interview data, we share unique insights into the lived experiences of Laura, one female project manager who recently managed a construction site in the Midlands in the UK. In contrast to previous research which indicates that female managers tend to conform to quite a traditional set of gender behaviours, Laura embraces a range of workplace appropriate gendered strategies, such as hard work and horseplay, together with sensitivity and caring. She draws from this mix of gendered strategies in negotiating between two different discourses of construction; one professional and one tough and practical. Her behaviour both reproduces the masculine ideals (through horseplay and heroic management) and opens up possibilities for modernising construction management (by caring). It is this combination of strategies that is at the heart of tacit expertise for Laura. Theoretically, the discussion adds to the development of a more nuanced understanding of management expertise as situated and person specific knowledge that draws on both the explicit and tacit. Specifically, the centrality of gendered strategies beyond the masculine ideals to success on site is highlighted

Thickness-dependent Electrochromic Properties of Amorphous Tungsten Trioxide Thin Films

Tungsten Trioxide (WO3) thin films were grown by thermal evaporation method to study the effect of film’s thickness on its electrochromic (EC) properties. The WO3 thin films of different thicknesses were grown on Indium Tin Oxide (ITO) coated glass and soda lime (bare) glass substrate held at room temperature. The surface composition of the thin films was investigated using X-ray photoelectron spectroscopy measurement, which showed the oxygen to tungsten atomic composition ratio to be nearly 2.97. The EC properties of the thin films were examined using electrochemical techniques. Cyclic-voltammetery shows the diffusion coefficient (D) of the intercalated H+ ion in the WO3 thin film increases with the film’s thickness. It turns out that the ‘thicker’ film exhibits better coloration efficiency (CE) as compared to the ‘thinner’ film. The coloration time was found to be independent of film thickness; however, the bleaching time increases as the film thickness increases