Research of Sulfur Concrete Compositions, Based on Local Raw Materials

Секция III : Ресурсо- и энергосберегающие строительные материалы и технологииВ данной статье авторами проанализирована возможность изготовления новых для отрасли Республики Беларусь строительных материалов на основе серного вяжущего (серобетонов), Исследованы прочностные свойства серобетонов, изготовленных с применением различных материалов, полученных из местных сырьевых источников, проанализировано влияние количественного процентного содержания серы как вяжущего в составе серобетона на прочность при одноосном кратковременном сжатии.=In this article, the authors analyzed the possibility of production of new construction materials for the construction industry of the Republic of Belarus based on sulfur binders (sulfur concrete), investigated the strength properties of sulfur concrete, based on various materials, obtained from local raw materials, analyzed the influence of the quantitative percentage of sulfur as a binder in sulfur concrete on the strength under uniaxial short-term compression

Research of Sulfur Concrete Compositions, Based on Local Raw Materials

Секция III : Ресурсо- и энергосберегающие строительные материалы и технологииВ данной статье авторами проанализирована возможность изготовления новых для отрасли Республики Беларусь строительных материалов на основе серного вяжущего (серобетонов), Исследованы прочностные свойства серобетонов, изготовленных с применением различных материалов, полученных из местных сырьевых источников, проанализировано влияние количественного процентного содержания серы как вяжущего в составе серобетона на прочность при одноосном кратковременном сжатии.=In this article, the authors analyzed the possibility of production of new construction materials for the construction industry of the Republic of Belarus based on sulfur binders (sulfur concrete), investigated the strength properties of sulfur concrete, based on various materials, obtained from local raw materials, analyzed the influence of the quantitative percentage of sulfur as a binder in sulfur concrete on the strength under uniaxial short-term compression

Strength Characteristics of Sulfur Concrete Made of Various Compositions

The article presents the results of an experimental study of the compressive strength properties of the sulfur concrete cube samples, made of various compositions: modified gypsum binders by the complex use of water preparation sludge, dolomite flour and plasticizer. It is shown that the modification of gypsum binders contributes to an increase of their strength characteristics

Fabrication and physicochemical properties of pectin/chitosan scaffolds

Scaffolds from chitosan and its combinations with other polymers are widely used for tissue engineering application. This is due to the favourable biological properties of chitosan such as antimicrobial activity, biocompatibility, biodegradability, cell adhesion and proliferation, etc. The aim of the study was the creation of 3D porous scaffolds based on pectin/chitosan polyelectrolyte complexes and study the influence of components ratio on their physico-chemical properties, as well as degradation behaviour in solutions modelling the media of the human body. Porous “sponge-like” polysaccharide films were produced using freeze-drying technique from gel-like pectin-chitosan polyelectrolyte complexes. The weight ratio of chitosan:pectin in complexes was varied in the range from 1:1 to 1:2. Obtained samples were characterized by infrared spectroscopy and scanning electron microscopy. It has been shown that pectin-chitosan films turned out to have sponge-like structure with highly interconnected pores with the size about 50-300 μm. It has been determined that all samples regardless of the chitosan:pectin ratio possess high swelling properties. The degradation profile of scaffolds in different media was studied. It has been determined that the largest weight loss is observed in water and reaches more than 80% after 1 day, while in NaCl and PBS solutions weight loss is approximately 50-60% after 25 days. For samples with different chitosan:pectin weight ratio, weight loss slightly rise with increasing amount of pectin. It has been shown that mesenchymal stem cells adhered to the surface of obtained pectin:chitosan porous scaffolds in viable state. Hence, it can be served as a potential material for tissue engineering applications

Construction of an infectious cDNA clone of Enterovirus 71: Insights into the factors ensuring experimental success

Enterovirus 71 (EV 71) is a causative agent of mild Hand Foot and Mouth Disease but is capable of causing severe complications in the CNS in young children. Reverse genetics technology is currently widely used to study the pathogenesis of the virus. The aim of this work was to determine and evaluate the factors which can contribute to infectivity of EV 71 RNA transcripts in vitro. Two strategies, overlapping RT-PCR and long distance RT-PCR, were employed to obtain the full-length genome cDNA clones of the virus. The length of the poly(A) tail and the presence of non-viral 3′-terminal sequences were studied in regard to their effects on infectivity of the in vitro RNA transcripts of EV 71 in cell culture. The data revealed that only cDNA clones obtained after long distance RT-PCR were infectious. No differences were observed in virus titres after transfection with in vitro RNA harbouring a poly(A) tail of 18 or 30 adenines in length, irrespective of the non-viral sequences at the 3′-terminus

The HIV type 1 epidemic in Belarus: predominance of Eastern European subtype A strains and circulation of subtype B viruses

To study the molecular epidemiology of HIV-1 in Belarus, where the rapid spread of HIV-1 has been registered since 1996, we obtained HIV-1 sequences from 30 individuals living in five cities in both the main geographic areas of the epidemic (Gomel and Minsk regions) and territories where spreading of the epidemic remains limited (Grodno region). Analysis of env V3 and gag p17/p24 sequences demonstrated that infections in all 12 injecting drug users and 14 of 18 individuals infected through sexual contacts were caused by subtype A viruses that are specific for the epidemic in the former Soviet Union (IDU-A viruses), while the remaining four infections were caused by phylogenetically unrelated to each other subtype B viruses. Extrapolation of these results to the total population of HIV-1-infected individuals in Belarus allowed us to estimate that IDU-A viruses account for nearly 95% of HIV-1 infections in Belaru

DURABILITY EVALUATION OF SULFUR CONCRETE OF VARIOUS COMPOSITION

Рассматривается проблема увеличения количества производимых побочных продуктов, в частности серы, в результате увеличения объема и повышения глубины нефтепереработки. Анализируется один из путей диверсификации рынка серы – использование её в нетиповых отраслях, в частности в строительстве, в качестве серобетона. Серобетон – новый строительный материал на основе серного вяжущего. Исследование свойств серобетонов актуально в связи с увеличением глубины нефтепереработки и её объемов. Влияние вида применяемого наполнителя на прочность серобетонов рассматривается при сжатии. Проанализировано влияние процентного содержания серы как вяжущего для получения серобетонов на прочность при сжатии.= With an increase in volume and an increase in the depth of oil refining, the amount of produced by-products, in particular sulfur, increases. One of the ways to diversify the sulfur market is to use it in non-standard industries, in particular, in construction. Sulfur concrete is a new building material based on sulfur binder. The study of the properties of sulfur concrete is relevant in connection with an increase in depth and an increase in oil refining volumes. In this article, the authors consider the influence of the type of filler used on the strength of sulfur concrete with short-term compression. In addition, the influence of the percentage of sulfur as a binder for the production of sulfur concrete on compressive strength was analyzed