Ипотечное страхование как драйвер роста ипотечного кредитования

В статье рассматривается необходимость и факторы развития ипотечного кредитования. Приводится краткий анализ альтернативных методов разрешения жилищного вопроса для россиян. Дается соответствующая оценка ипотечного страхования как фактора развития ипотечного кредитования

(I) Early Alterations of Apoptosis and Cell Proliferation in Azoxymethane-initiated Rat Colonic Epithelium (II) Expression of Bcl-2, Bax and Bcl-XL proteins in the azoxymethane-induced rat colonic adenocarcinomas

(I) Early Alterations of Apoptosis and Cell Proliferation in Azoxymethane-initiated Rat Colonic Epithelium(II) Expression of Bcl-2, Bax and Bcl-XL proteins in the azoxymethane-induced rat colonic adenocarcinoma

Ferroelectric, Pyroelectric and Piezoelectric Effects of Hafnia and Zirconia Based Thin Films

Ferroelectric materials are of great interest for several applications. On the one hand, theferroelectric field effect transistor (FeFET) is a promising candidate for future high density, nonvolatile memory devices. On the other hand, in the recent years the energy related applications such as pyroelectric and piezoelectric energy harvesting as well as electrocaloriccooling and electrostatic energy storage attracted wide interest. The conventional ferroelectricmaterials such as lead zirconatetitanate (PZT) are not completely CMOS compatible and therefore a high-density integration for memory application could not be realized up to date.Furthermore, PZT has environmental issues due to the contained lead.Ferroelectric hafnium oxide, which was first reported in 2011, can overcome the mentioneddrawbacks of the conventional ferroelectrics, since it is fully CMOS compatible. Theferroelectric phase is stabilized by doping with various dopants. Furthermore, a mixture ofhafnium and zirconium oxide (Hf1-xZrxO2) does also stabilize the ferroelectric phase.In this thesis, hafnia and zirconia based ferroelectrics are deposited by a novel CSD (chemicalssolution deposition) process and are characterized in respect to their ferroelectric, piezoelectric and pyroelectric properties. The ferroelectric nature of hafnium oxide is shown for severaldopants as well as for Hf1-xZrxO2 with different compositions and for pure ZrO2. Especially inthe case of ZrO2 this is very surprising since ZrO2 was studied for many years and for severalapplications without revealing ferroelectric properties. In contrast to atomic layer deposition(ALD), which is most commonly used for the deposition of hafnia and zirconia basedferroelectric film, the CSD technique is appropriate for deposition of thicker films without a strong reduction of the ferroelectric response. This makes hafnia and zirconia basedferroelectrics suitable for applications, where larger film thicknesses are unavoidable such aspiezoelectric and electrocaloric cooling devices

An extensive study of the influence of dopants on the ferroelectric properties of HfO 2

The ferroelectric properties of hafnium oxide based thin films prepared by chemical solution deposition (CSD) are investigated. In this extensive study, a wealth of strongly different dopants (size and valence) and dopant concentrations is used to induce ferroelectricity in 42 nm thin films. Using the same precursors and preparation conditions for all dopants a good comparability is given. In particular, the dopant size appears to have a crucial impact on the resulting ferroelectric properties. For smaller dopants only a small ferroelectric response is observed whereas for larger dopants the remanent polarization is increased significantly. The crystal phase for varying dopant concentrations and dopant sizes is investigated by grazing incidence X-ray diffractions (GI-XRD). A dominating cubic phase is found for doping concentrations showing the highest remanent polarization. Similar to first CSD studies on Y:HfO2, this is reflected in a prominent wake-up behavior, which is attributed to a phase transition from cubic to orthorhombic during field cycling

Evidence for oxygen vacancies movement during wake-up in ferroelectric hafnium oxide

The wake-up effect which is observed in ferroelectric hafnium oxide is investigated in yttrium doped hafnium oxide prepared by chemical solution deposition. It can be shown that not the amount of cycles but the duration of the applied electrical field is essential for the wake-up. Temperature dependent wake-up cycling in a range of −160 °C to 100 °C reveals a strong temperature activation of the wake-up, which can be attributed to ion rearrangement during cycling. By using asymmetrical electrodes, resistive valence change mechanism switching can be observed coincident with ferroelectric switching. From the given results, it can be concluded that redistribution of oxygen vacancies is the origin of the wake-up effect

An alternative approach to analytic force computation in permanent-magnet machines

We present an alternative approach to analytic force computation in permanent-magnet machines, focusing on the tangential forces that generate the armature and the cogging torque. We extend previously presented methods using conformal mapping to overcome the limits imposed by the singularity of the magnetic flux density at the tooth tip that occurs during the transformation. Using our approach, the cogging and armature torques developed in lightly loaded electric machines can be computed without these limits and without introducing auxiliary parameters. We also revisit Maxwell's stress theory to compute the force on the interface of two materials with different permeabilities, in contrast to the common application to compute the force on a rigid body placed in an electromagnetic field. Using this technique, we then calculate the forces at the slot sides so that the influence of the machine design parameters on the result is directly available

Pulse wake-up and breakdown investigation of ferroelectric yttrium doped HfO 2

The wake-up effect in yttrium doped hafnium oxide is investigated by pulse measurements, revealing the initial distribution of oxygen vacancies within symmetrical and asymmetrical layer stacks. It is shown that single pulses are sufficient to achieve a significant wake-up, whereby additional pulses lead to a stronger wake-up. Further cycling induces a degradation of the devices, which is explained by generation of oxygen vacancies and results in an electroforming step where subsequently resistive valence change mechanism switching is observed. The degradation and therefore the generation of oxygen vacancies show a strong frequency dependence, whereby the device lifetime is strongly increased for increasing frequencie

Analytical force calculation in brushless-DC motors I: an alternative approach

In this paper, we focus on the analytical calculation of the tangential forces that generate the armature and the cogging torque in brushless dc machines. We extend previously presented methods using conformal mapping to (i) avoid the singularity of the magnetic flux density at the tooth tip during the transformation and thereby overcome the limitations of this approach with respect to the calculation of the cogging and armature torques developed in electric machines, and (ii) calculate the forces at the slot sides so that the influence of the machine design parameters on the result is directly available