77 research outputs found
Optical and EXAFS studies of NaNbO3 - Gd1/3NbO3 solid solutions
This study is supported by Russian Science Foundation (project 19-12-00205)
The Structural Phase Transition of the Relaxor Ferroelectric 68%PbMg1/3Nb2/3O3-32%PbTiO3
Neutron scattering techniques have been used to study the relaxor
ferroelectric 0.68PbMg1/3Nb2/3O3-0.32PbTiO3 denoted in this paper as
0.68PMN-0.32PT. On cooling, these relaxor ferroelectrics have a long-range
ordered ferroelectric phase and the composition is close to that at which the
ferroelectric structure changes from rhombohedral to tetragonal. It was found
that above the Burns temperature of about 600K, the transverse optic mode and
the transverse acoustic mode are strongly coupled and a model was used to
describe this coupling that gave similar parameters to those obtained for the
coupling in PMN. Below the Burns temperature additional quasi-elastic
scattering was found which increased in intensity as the sample was cooled down
to the ferroelectric transition temperature but then decreased in intensity.
This behaviour is similar to that found in PMN. This scattering is associated
with the dynamic polar nano-regions that occur below the Burns temperature. In
addition to this scattering a strictly elastic resolution limited peak was
observed that was much weaker than the corresponding peak in pure PMN and which
decreased in intensity on cooling below the ferroelectric phase whereas for
PMN, which does not have a long-range ordered ferroelectric phase, the
intensity of this component increased monotonically as the sample was cooled.
The results of our study are compared with the recent measurements of Stock et
al. [PRB 73 064107] who studied 0.4PMN-0.6PT. The results are qualitatively
consistent with the random field model developed to describe the scattering
from PMN
Giant magnetoimpedance effect in nanocrystalline microwires
We studied GMI effect and magnetic properties of Finemet-type FeCuNbSiB microwires. We observed that GMI magnetic field and frequency dependences and magnetic softness of composite microwires produced by the Taylor-Ulitovski technique can be tailored either controlling magnetoelastic anisotropy of as-prepared FeCuNbSiB microwires or controlling their structure by heat treatment or changing the fabrication conditions. GMI effect has been observed in as-prepared Fe-rich microwires with nanocrystalline structure.This work was supported by EU ERA-NET programme under project "SoMaMicSens" (MANUN ET-2010-Basque-3), by EU under FP7 "EM-safety" project, by Spanish Ministry of Science and Innovation, MICINN under Project MAT2010-18914, by the Basque Government under Saiotek 11 MICMAGN project (S-PE11UN087) and by federal target program "Scientific and scientific-pedagogical personnel of innovative Russia", state contract No. 14.18.21.0783
Comparative assessment of antioxidant activity of chicory products
There are various methods for determining the antioxidant activity. They are differing by the source of oxidation, oxidized compounds and methods for the measurement of oxidized compounds. Methods for determination of antioxidant activity provide a wide range of results, so the evaluation of the antioxidant activity should be carried out in several ways, and the results should be interpreted with caution. In assessing antioxidant capacity is necessary to consider not only the nature and content of the reducing agent in the test facility, but also the possibility of their mutual influence. The objects of research in this research work were Instant chicory (Leroux), Fried chicory (Leroux), Instant chicory (LLC Favorit), Instant chicory (LLC SlavKofe), Instant chicory with hawthorn (Iceberg Ltd and K), Instant chicory (LLC Flagistom), Instant chicory (Ltd. Around the World), Instant chicory (LLC Beta +), Chicory flour (Leroux), Chicory flour. Antioxidant activity of the products of chicory determined by spectrophotometric (using adrenaline and 2,2 – diphenyl- 1-picrylhydrazyl), and amperometric methods. These results indicate that chicory products possess antioxidant activity but not give fully correlated with each other results. The highest antioxidant activity have fried products from chicory – Instant chicory (LLC SlavKofe) and Instant chicory with hawthorn (Iceberg Ltd and K). No fried products from chicory (Chicory flour (Leroux)) have lower antioxidant activity then fried products from chicory. Because during frying new compounds are formed – chikoreol, which comprises acetic and valeric acid, acrolein and furfural, furfuryl alcohol, diacetyl. Best convergence results provide spectrophotometric methods using epinephrine and 2,2 – diphenyl-1-picrylhydrazyl
BIOTECHNOLOGY FOR KEFIR WITH NEW QUALITIES
Summary. Modern kefir production is based on the milk acidification process with the use of kefir grains by alcohol and lactic acid fermentation. Casein large molecules are fermented by sourdough’ microorganisms, and as a result they are digested much more effectively by the body. Thanks to a special composition of the sourdough’ microbiota, which composed of yeast, lactic acid and acetic acid bacteria, kefir is especially useful for a person of any age, helps to restore energy balance of human body, beneficial effects on the nervous system and metabolic processes. On the basis of the traditional technology of kefir production, which includes processes of normalization, homogenization, pasteurization, cooling to a temperature of fermentation, injection of sourdough, has been developed kefir production technology with the introduction of the ferment transglyutaminase that provides the generation of its own lactoferrin by the composition of microorganisms in kefir grains. Lactoferrin content ranges from 500 to 1100 mg/l, which is considerably higher than in the control group (300 mg/l). Lactoferrin is natural antioxidant that prevents the effect of early aging of the organism, contributes to the preservation of a healthy gastrointestinal tract. In many ways lactoferrin contributes to the preservation of health and fully supports the active longevity
Local atomic structure of niobates and titanates from X-ray absorption spectroscopic data
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