Prevention of HIV and Associated Infections among Adolescents and Young People at High Risk of Infection : Methodology Guide

Methodology Guide on Prevention of HIV and Associated Infections among Adolescents and Young People at High Risk of Infection was prepared as part of project “Building capacity in prevention of HIV and associated infections among youth at high risk in the Northern Dimension area” (cf. www.ndphs.org/?database,view,project,1467) co-funded by the European Union. The project was implemented from September 1, 2013 to August 31, 2015 by the project consortium led by Secretariat of the Northern Dimension Partnership in Public Health and Social Well-being (NDPHS) and including also Regional NGO “Stellit”, National Institute for Health and Welfare, Kaliningrad Regional Non-governmental Youth Organisation “Young Leaders Army” (YLA), Social AIDS Committee and Baltic HIV Association. The Methodology Guide contains overview of theories applicable for addressing the priorities of HIV and associated infections prevention among adolescents and young people at high risk of infection, theories which might be used to evaluate the effectiveness of prevention programs. It provides the results of assessment of needs of children and young people at high risk of infection in prevention programs, overview of prevention programs implemented in Russia, Latvia, Poland, Finland and Germany which might be recommended to be spread to other countries of the NDPHS and examples of tool which might be used in prevention work. The Methodology Guide might be useful for authorities, representatives of governmental organizations, NGOs, international organizations, public health specialists and other experts involved into HIV and associated infections prevention among children and young people. The Methodology Guide is available for downloading at: http://urn.fi/URN:NBN:fi-fe2015102715069. Other methodological materials produced within the project can be downloaded at: https://www.thl.fi/en/web/thlfi-en/about-us/organisation/departments-and-units/administration-and-development/planning/international-affairs-unit/projects

2-5 pyrochlore relaxor ferroelectric Cd2Nb2O7 and its Fe2+/Fe3+ modifications

Copyright 2001 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.International audienceThe weak-field dielectric dispersion (100 Hz-1.8 GHz) studies both of pure and Fe2+/Fe3 modified Cd2Nb2O7 ceramics over the temperature range of 90-380 K are presented and discussed from the viewpoint of relaxor and glassy properties of the system. It is revealed that Cd2Nb2O7 pyrochlore is intolerant of the addition of 25 mol % Fe2+ or Fe3+ for Cd2+. From the x-ray diffraction analysis, pure Cd2Nb2O7 forms a single-phase pyrochlore, while the compositions Cd1.5Fe0.52+Nb2O7 and Cd1.5Fe0.53+Nb2O7 give CdNb2O6 columbite doped with Fe2+ or Fe3+ on the Cd sites (<8 and <2 mol %, respectively), except for minor amount of parasitic hematite. The novel CdNb2O6 type compounds are not ferroelectrics, unlike Cd2Nb2O7. In the latter, at TC=196 K the dielectric relaxation due to the motion of ferroelectric domain walls driven by an external ac electric field is observed. A polydispersive dielectric response of Cd2Nb2O7 around 188 K has characteristics of the relaxor ferroelectrics with glassy behavior (like PMN). Near the characteristic freezing temperature of the zero-field-cooled state (Tf=183 K) the dielectric absorption spectra and the relaxation-time distribution strongly broaden and tend to flatten out, while below Tf the imaginary part of the dielectric permittivity becomes nearly frequency independent. The dielectric response of Cd2Nb2O7 dominating far below TC (around 150 K) and that of Fe2+/Fe3+ doped CdNb2O6 between 90 and 380 K are typical of glass-forming systems at temperature far above Tglass. The relaxational process is characterized by (i) a significant frequency dependence of the peak permittivity position, (ii) non-Arrhenius behavior, and (iii) increasing asymmetry of the dielectric absorption spectrum at the low-frequency side with decreasing temperature, without broadening the relaxation-time distribution and freezing the peak-absorption frequency. It is proposed that although the nature of structural disorder in Cd2Nb2O7 pyrochlore and Fe2+/Fe3+ doped CdNb2O6 columbite is different, in both systems the off-center displacements of the A-site ions act as a random field and are responsible for the relaxor and dipolar glass-like behavior upon cooling. The Debye-like HF dielectric relaxation (1 MHz-1.8 GHz) observed both in Cd2Nb2O7 and its isostructural analog Cd2Ta2O7 at RT and higher (a centrosymmetric phase) is attributed to fluctuations in polarization of the dynamically reoriented O(7th)-Cd-O(7th) dipoles due to dynamical off-center location of Cd ions

Studying the Properties of Composites with a Polyvinylchloride Matrix and Meadow-Grass-Hay Filler

Abstract: Polymer composites with a polyvinylchloride matrix and crushed meadow-grass-hay filler (MGHF) were obtained by hot pressing. The influence of the content of MGHF in a composition on its physicomechanical properties was researched. It was established that the increment of MGHF content in the composition of a composite leads to change in the values of its properties, most of which are not inferior to those of similar materials filled with wood flour. © 2022, Pleiades Publishing, Ltd

An Investigation of Complexes of Lignin Found in Plant Raw Materials as a Natural Binder in Obtaining Plastic in Closed Molds

Abstract: It has been suggested that lignin of wood and plant origin is directly involved in the formation of plastics without the addition of binders due to the formation of a net structure. The performed studies using DSC showed the presence of two peaks under the influence of temperature and water—hydrolytic destruction of the lignin–carbohydrate complex and further polycondensation of its “fragments” into a cross-linked polymer with the formation of plastic. The use of catalysts such as polyoxometalates (by the example of manganese-containing sodium vanadomolybdophosphate) makes it possible to carry out preliminary partial destruction of lignin and obtain plastics under “softer” conditions. In this case, it is necessary to take into account the different chemical structure and lignin content in the initial molding material, which determines not only the conditions for obtaining, but also the properties of the resulting material. © 2023, Pleiades Publishing, Ltd