The present study was aimed at revealing the influence of the mechanical stress induced by water molecule adsorption on the composition of crystalline phases in the ZrO2 + 3 mol% Y2O3-nanoparticles. ...Three basic methods were used to determine the phase transition: neutron diffraction, Raman microspectroscopic scanning, and X-ray diffraction. The fact of reversible phase-structural β → α transformation and the simultaneous presence of two polymorphic structural modifications (β is the phase of the tetragonal syngony and α of monoclinic syngony in nanosized particles (9 nm)) under normal physical conditions was established by these methods. An assumption was made regarding the connection of the physical mechanism of transformation of the extremely nonequilibrium surface of nanoparticles with electronic exchange of the material of the near-surface layer of nanoparticles with the adsorption layer through donor–acceptor interaction. The principal possibility of creating direct-acting hydroelectric converters based on nanoscale YSZ (Yttria-Stabilized Zirconia) systems due to the reversible character of the considered effect was shown.
The paper considers the new effects of the nanoscale state of matter, which open up prospects for the development of electronic devices using new physical principles. The contacts of chemically ...homogeneous nanoparticles of yttrium-stabilized zirconium oxide (ZrO2—x mol% Y2O3, x = 0, 3, 4, 8; YSZ) with different sizes of 7.5 nm and 9 nm; 7.5 nm and 11 nm; and 7.5 nm and 14 nm, respectively, was studied on direct current using nanostructured objects in the form of compacts obtained by high-hydrostatic pressure (HP-compacts of 300MPa). A unique size effect of the nonlinear (rectifying-type contact) dependence of the electrical properties (in the region U < 2.5 V, I ≤ 2.7 mA) of the contact of different-sized YSZ nanoparticles of the same chemical composition is revealed, which indicates the possibility of creating semiconductor structures of a new type (homogeneous electronics). The electronic structure of the near-surface regions of nanoparticles of studied oxide materials and the possibility of obtaining specifically rectifying properties of the contacts were studied theoretically. Models of surface states of the Tamm-type are constructed considering the Coulomb long-range action. The discovered energy variance and its dependence on the curvature of the surface of nanoparticles made it possible to study the conditions for the formation of a contact potential difference in cases of nanoparticles of the same radius (synergistic effect), different radii (doped and undoped variants), as well as to discover the possibility of describing a group of powder particles within the Anderson model. The determined effect makes it possible to solve the problem of diffusion instability of semiconductor heterojunctions and opens up prospects for creating electronic devices with a fundamentally new level of properties for use in various fields of the economy and breakthrough critical technologies.
The dimensional effect of electric charge storage with a density of up to 270 μF/g by the hydrated ZrO2-nanoparticles system was determined. It was found that the place of localization of different ...charge carriers is the generalized heterophase boundary-nanoparticles surface. The supposed mechanism of the effect was investigated using the theory of dispersed systems, the band theory, and the theory of contact phenomena in semiconductors, which consists of the formation of localized electronic states in the nanoparticle material due to donor–acceptor interaction with the adsorption ionic atmosphere. The effect is relevant for modern nanoelectronics, microsystem technology, and printed electronics because it allows overcoming the basic physical restrictions on the size, temperature, and operation frequency of the device, caused by leakage currents.
The present study was aimed at revealing the influence of the mechanical stress induced by water molecule adsorption on the composition of crystalline phases in the ZrO
+ 3 mol% Y
O
-nanoparticles. ...Three basic methods were used to determine the phase transition: neutron diffraction, Raman microspectroscopic scanning, and X-ray diffraction. The fact of reversible phase-structural β → α transformation and the simultaneous presence of two polymorphic structural modifications (β is the phase of the tetragonal syngony and α of monoclinic syngony in nanosized particles (9 nm)) under normal physical conditions was established by these methods. An assumption was made regarding the connection of the physical mechanism of transformation of the extremely nonequilibrium surface of nanoparticles with electronic exchange of the material of the near-surface layer of nanoparticles with the adsorption layer through donor-acceptor interaction. The principal possibility of creating direct-acting hydroelectric converters based on nanoscale YSZ (Yttria-Stabilized Zirconia) systems due to the reversible character of the considered effect was shown.
The dimensional effect of electric charge storage with a density of up to 270 μF/g by the hydrated ZrO
-nanoparticles system was determined. It was found that the place of localization of different ...charge carriers is the generalized heterophase boundary-nanoparticles surface. The supposed mechanism of the effect was investigated using the theory of dispersed systems, the band theory, and the theory of contact phenomena in semiconductors, which consists of the formation of localized electronic states in the nanoparticle material due to donor-acceptor interaction with the adsorption ionic atmosphere. The effect is relevant for modern nanoelectronics, microsystem technology, and printed electronics because it allows overcoming the basic physical restrictions on the size, temperature, and operation frequency of the device, caused by leakage currents.
Background
Managed entry agreements (MEAs) are a set of instruments to facilitate access to new medicines. This study surveyed the implementation of MEAs in Central and Eastern Europe (CEE) where ...limited comparative information is currently available.
Method
We conducted a survey on the implementation of MEAs in CEE between January and March 2017.
Results
Sixteen countries participated in this study. Across five countries with available data on the number of different MEA instruments implemented, the most common MEAs implemented were confidential discounts (
n
= 495, 73%), followed by paybacks (
n
= 92, 14%), price-volume agreements (
n
= 37, 5%), free doses (
n
= 25, 4%), bundle and other agreements (
n
= 19, 3%), and payment by result (
n
= 10, >1%). Across seven countries with data on MEAs by therapeutic group, the highest number of brand names associated with one or more MEA instruments belonged to the Anatomical Therapeutic Chemical (ATC)-L group, antineoplastic and immunomodulating agents (
n
= 201, 31%). The second most frequent therapeutic group for MEA implementation was ATC-A, alimentary tract and metabolism (
n
= 87, 13%), followed by medicines for neurological conditions (
n
= 83, 13%).
Conclusions
Experience in implementing MEAs varied substantially across the region and there is considerable scope for greater transparency, sharing experiences and mutual learning. European citizens, authorities and industry should ask themselves whether, within publicly funded health systems, confidential discounts can still be tolerated, particularly when it is not clear which country and party they are really benefiting. Furthermore, if MEAs are to improve access, countries should establish clear objectives for their implementation and a monitoring framework to measure their performance, as well as the burden of implementation.
Rare earth down convertors ZBLA doped glasses for solar cells encapsulation. Display omitted
•We measure the performances of silicon solar cells using rare earth doped glasses.•The influence of Yb3+ ...doping level was studied for the Pr3+–Yb3+ co-doped ZBLA.•The optimum doping concentration is of 0.5–2mol% Yb3+.
The non-absorption of photons with energies below the bandgap (Eg) and the thermalization of photons with energies higher than Eg are the dominant loss processes of single-junction solar cells. Rare earth doped glasses give the opportunity to convert the incident photons wavelength and hence to increase or decrease their energies. The conversion of photons energies by “up or down conversion” leads to the possibility to increase the efficiencies of all classes of single-junction solar cells. Depending on the nature of doping materials, two low energy photons can be converted into one high-energy photon (up-conversion), or one high energy photon, can be converted into two low energy photons (down-conversion). In this paper, Pr3+–Yb3+ down-conversion co-doped ZBLA glasses were tested as encapsulation materials for silicon solar cells. The J–V characterizations were done under solar simulator irradiation. The influence of Yb3+ concentration on the solar cells performances was investigated, showing that an optimum value between 0.5 and 2mol% conducts to an increase of the device efficiency comparing to mono-doped ZBLA material.
In this paper we made a study on the effect of films thickness on the electrical conduction properties of nanostructured TiO
2 thin films deposited by d.c. reactive sputtering. The deposition was ...performed on heated (573
K) glass substrates, using water vapor as reactive gas. The electrical conductivity of the films was investigated in the temperature range 13–320
K. The temperature dependence of electrical conductivity between 80 and 320
K indicated that electrical conductivity in the films was controlled by potential barriers caused by depletion of carriers at grain boundaries in the material. Values of grain barrier heights and surface trap density at the grain boundaries were extracted from the high temperature data for the investigated samples. Both the grain barrier heights and surface trap density at the grain boundaries were found to depend significantly on film thickness into the deposition process. The low-temperature (
T
<
80
K) conductivity of the films was described in terms of variable-range hopping (VRH) conduction. Characteristic parameters describing the low-temperature conductivity, such as the hopping distance, hopping energy and density of states were determined, and their values as a function of film thickness were discussed in the light of variable-range hopping conduction model.
Osteoporotic vertebral fractures can lead to late collapse which often cause kyphotic spinal deformity, persistent back pain, decreased lung capacity, increased fracture risk and increased mortality. ...The purpose of our study is to compare the efficacy and safety of vertebroplasty against conservative management of osteoporotic vertebral fractures without neurologic symptoms. A total of 66 patients with recent OVF on MRI examination were included in the study. All patients were admitted from September 2009 to September 2012. The cohort was divided in two groups: first study group consisted of 33 prospectively followed consecutive patients who suffered 40 vertebral osteoporotic fractures treated by percutaneous vertebroplasty (Group 1), and the control group consisted of 33 patients who suffered 41 vertebral osteoporotic fractures treated conservatory because they reffused vertebroplasty (Group 2). Vertebroplasty with PMMA was performed in 30 patients on 39 VBs, including four thoracic vertebras, 27 vertebras of the thoracolumbar jonction and 8 lumbar vertebras. In the Group 2 were included 30 patients with 39 OVFs (four thoracic vertebras, 23 vertebras of the thoracolumbar junction and 11 lumbar vertebras). In our study on OVF, vertebroplasty delivered superior clinical and radiological outcomes over the first year from intervention when compared to consevative treatment of patients with osteoporotic compression fractures without neurological deficit.
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