Плазмодинамический синтез двукомпонентного Zn-Bi[2]O[3] порошкообразного ультрадисперсного материала для изготовления варисторной керамики

We report the observation of ferroelectricity in capacitors based on hafnium-zirconium-oxide. Hf0.5Zr0.5O2 thin films of 7.5 to 9.5 nm thickness were found to exhibit ferroelectric polarization-voltage hysteresis loops when integrated into TiN-based metal-insulator-metal capacitors. A remnant polarization of 16 C/cm2 and a high coercive field of 1 MV/cm were observed. Further proof for the ferroelectric nature was collected by quasi-static polarization-voltage hysteresis, small signal capacitance-voltage, and piezoelectric measurements. Data retention characteristics were evaluated by a Positive Up Negative Down pulse technique. No significant decay of the initial polarization state was observed within a measurement range of up to two days

The leadership disease...and its potential cures

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Leadership development and executive education have taken on increased prominence in recent years. The natural tendency is to approach the subject of leadership as a hierarchically-based process that is focused on higher-level individual leaders influencing lower-level followers. This tendency is consistent with myths surrounding charismatic and heroic visionary leaders who are often portrayed as single-handedly inspiring and directing their organizations to new heights. Unfortunately, these simplistic portrayals of leadership are promulgated by the media and desired by the consuming public. However, this kind of framing of leadership is dangerous: it lays the seeds of centralization of power, which can have innumerable detrimental outcomes. Accordingly, we explore two potent antidotes to this simplistic hierarchical formulation of leadership that have become an increasing focus of leadership research: self-leadership and shared leadership

In vivo determination of extracellular concentration of amino acids in the rat hippocampus. A method based on brain dialysis and computerized analysis

11 páginas, 3 figuras, 5 tablas.Extracellular (EC) concentrations of amino acids were determined in the rat dentate gyrus by means of non-linear regression analysis of ‘in vivo’ brain dialysis data, considering a simple model of diffusion through a dialysis membrane. The apparent diffusion constants (K) of several amino acids were also calculated in the ‘in vivo’ situation. While putative amino acid neurotransmitters (glutamate, aspartate and γ-aminobutyric acid (GABA) were present in the EC fluid at the low micromolar range (0.8–2.9 μM), glutamine was by far the most prominent (193.4 μM). The values of intra/extracellular concentration ratios formed 3 groups: (a) high (>2000) for putative neurotransmitters; (b) low (<100) for serine, glutamine, arginine and α-alanine; and (c) intermediate (about 400) for taurine. The ‘in vivo’ calculatedK values proved useful for estimation of both basal and changing EC concentrations of amino acids in relatively brief perfusions. These data were evaluated in terms of the functional significance of absolute EC concentrations and tissue-EC fluid ratios. Present findings indicate the simultaneous existence of both an inhibitory and an excitatory tonus as well as the utility of high intra/extracellular concentration ratios in determination of the possible neurotransmitter role of specific amino acids.This work was partially supported by the Fondo de Investigaciones Sanitarias (F.I.S.S.S. 85/1070). O.H. is a fellow of the F.I.S.S.S.Peer reviewe

Bifacial n-type solar modules : indoor and outdoor evaluation

There is an increased energy yield for n-type bifacial solar modules as compared with n-type monofacial modules. However, the benefit of bifaciality depends on several factors, such as module height, ground reflectivity, distance between modules, etc. This work enriches the understanding of the correlation between laboratory measurements and outdoor performance of bifacial modules. Indoor measurements of monofacial and bifacial modules, containing n-type bifacial cells of similar technology, were performed at PI Berlin (Germany). Their outdoor performance was monitored in El Gouna (Egypt), where the yield in terms of Wh/Wp was compared, and in Winterthur (Switzerland), where the influence of module height and ground reflectivity was studied. In El Gouna, an average yield gain of 22.3% in terms of Wh/Wp was measured for a bifacial module as compared with a monofacial module, over the first eight months of 2014. A maximum average monthly gain of 25.6% was reached in the month of August. A peak power output of 426 W was registered. In Winterthur, the application of a white foil beneath a bifacial module showed a gain of 7.6% in power output divided by the incident irradiance on the front side, as compared with a gravel covered ground. The power/irradiance gain was 9.7% when the module was raised from 0 cm to 64 cm above the ground level