Influence of Synthesis Conditions on the Structure and the Surface State of Zirconia Nanoparticles

The paper studies the influence the nature of the salt anion and the base of precipitant, used in the synthesis of zirconia nanoparticles by chemical coprecipitation, on process parameters of the hydrogel drying, xerogel dehydration and crystallization, and the occurrence of polymorphic transitions in crystalline oxide systems are considered in this paper. The features of the structure, surface condition and properties of zirconia nanoparticles, which were obtained by using different precursors, are examined by FTIR and EPR spectroscopy, DSC and XRD methods. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516

The spectral energy distribution of fermi bright blazars

We have conducted a detailed investigation of the broadband spectral properties of the γ-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi γ-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray/γ-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. The SED of these γ-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual log ν-log ν Fν representation, the typical broadband spectral signatures normally attributed to a combination of low-energy synchrotron radiation followed by inverse Compton emission of one or more components. We have used these SED to characterize the peak intensity of both the low- and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, αro, and optical to X-ray, αox, spectral slopes) and from the γ-ray spectral index. Our data show that the synchrotron peak frequency (νSpeak) is positioned between 1012.5 and 1014.5 Hz in broad-lined flat spectrum radio quasars (FSRQs) and between 10 13 and 1017 Hz in featureless BL Lacertae objects. We find that the γ-ray spectral slope is strongly correlated with the synchrotron peak energy and with the X-ray spectral index, as expected at first order in synchrotron-inverse Compton scenarios. However, simple homogeneous, one-zone, synchrotron self-Compton (SSC) models cannot explain most of our SED, especially in the case of FSRQs and low energy peaked (LBL) BL Lacs. More complex models involving external Compton radiation or multiple SSC components are required to reproduce the overall SED and the observed spectral variability. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are detected in the LBAS sample, only less than 13% of known bright FSRQs and LBL BL Lacs are included. This suggests that the latter sources, as a class, may be much fainter γ-ray emitters than LBAS blazars, and could in fact radiate close to the expectations of simple SSC models. We categorized all our sources according to a new physical classification scheme based on the generally accepted paradigm for Active Galactic Nuclei and on the results of this SED study. Since the LAT detector is more sensitive to flat spectrum γ-ray sources, the correlation between νSpeak and γ-ray spectral index strongly favors the detection of high energy peaked blazars, thus explaining the Fermi overabundance of this type of sources compared to radio and EGRET samples. This selection effect is similar to that experienced in the soft X-ray band where HBL BL Lacs are the dominant type of blazars. © 2010 The American Astronomical Society

Avalanches of the USSR

International Conference on Low Temperature Science. I. Conference on Physics of Snow and Ice, II. Conference on Cryobiology. (August, 14-19, 1966, Sapporo, Japan

CRYOGLOBULINS IN CASE OF RHEUMATOID ARTHRITIS IN CHILDREN: CONNECTION WITH THE AGE FACTOR AND CHANGES IN THE URINE ANALYSIS

33 healthy children and 39 patients withjuvenile rheumatoid arthritis have been studied. The level of cryoglobulins has been up to 80 mcg/ml in healthy children (43,5+28,3 mcg/ml) being decreased with the age. The level of cryoglobulins has been accounted for 651 mcg/ml(91,2+110,2 mcg/ml) being increased with the age in children with juvenile rheumatoid arthritis. Significant correlation between the level of cryoglobulins and activity of disease has been revealed. There were no differences of the level of cryoglobulins in children with systemic and articular forms of arthritis as wellas in children with changed and normal urine analyses

A contribution to the knowledge of bryophytes in polar areas subjected to rapid deglaciation: a case study from southeastern Spitsbergen

The paper provides a list of 54 species of bryophytes (48 mosses and six liverworts) collected from Spitsbergen, the largest island of the Arctic Svalbard archipelago (Norwegian Arctic), in 2016. They were collected mainly from its southeastern coast (Sørkapp Land and Torell Land), which has been rapidly abandoned by glaciers in the last few decades and is heavily under-investigated bryologically. The most interesting and phytogeographically important findings are the mosses Bryum salinum, Campylium longicuspis, Coscinodon cribrosus, Orthogrimmia sessitana, Pogonatum dentatum, Polytrichum juniperinum, Sanionia georgicouncinata, Schistidium frigidum, and S. pulchrum, and the liverwort Cephalozia bicuspidata. For each species, a short taxonomic and phytogeographical comment is provided, and the distribution of 12 rare or otherwise phytogeographically interesting species in Svalbard is shown on maps

Молодежь в политической и социокультурной жизни Африки

Представляемая работа является первым за последние 25 лет монографическим изданием, посвященным проблемам африканской молодежи и ее роли в становлении и развитии молодых государств. Особое внимание уделяется вопросам социализации и формирования идентичности как в традиционном, так и в современном обществах, спецификt молодежных политических движений и молодежной политике государственных структур. Затрагиваются вопросы демографического фактора и влияния средств массовой информации на решении проблемы занятости