THE USE OF PHOTOCATALYTIC CONCRETES IN ROAD CONSTRUCTION

The article discusses the possibility of reducing the atmospheric environmental load of highways by applying compositions with photocatalytic properties to acoustic screens. It is found that the amount of nitrogen oxides on the territory of the city of Moscow exceeds the MPC norms. Therefore, a potential way to reduce the level of the average daily and maximum one-time MPC of nitrogen oxides is proposed, when using coatings of traditional acoustic screens with photocatalytic compositions. Titanium dioxide in anatase form is considered as a photocatalytic agent. To reduce the density and increase the porosity of cement compositions, a cellulosic suspension obtained by saturation in an aqueous medium with subsequent homogenization is introduced. The effect of cellulose in the considered cement systems in combination with a photocatalytic agent has been investigated. By the method of mathematical planning, a two-factor compositional experiment is compiled. In result, the degrees of influence of titanium dioxide and cellulose additives on the strength, density and water absorption of the composites under study are established. The study of the structure of the obtained composites shows that TiO2 is mainly located on the surface of cellulose fibers, which theoretically increases the useful surface for photocatalytic reactions and, as a consequence, the final efficiency of the compositions.

Optimization of Dry Construction Mix with the Addition of Biochar from Reclaimed Rice Straw in the Agro-Industrial Complex

Currently, the actual problem is the disposal of various by-products of the agro-industrial complex. This direction practically does not develop, but is solved only by burning them, which leads to air pollution. The article contains physical and chemical studies of a byproduct from rice production, namely rice straw. In the process of recycling rice straw at a temperature of 600°C, biochar is formed, which can be used as a micro-filling additive for dry mortar. Using the method of mathematical planning of the experiment (FFE 2k), optimization was carried out and the optimal composition of the dry mortar was obtained, containing up to 10% of biochar. It has been established that the introduction of biochar in the optimal dosage improves the physical and mechanical properties of the dry mortar in comparison with the control composition on average by: average density – 3%, water absorption – 17%, compressive strength – 12%, tensile strength at bending – 24%, adhesion strength – 55%..

Investigation of the deformation and strength characteristics of the thread connection in the manufacture of products from fur waste

By the method of mathematical planning of the experiment, regression equations were obtained for the breaking load and the breaking relative elongation of the thread connection of a special furrier’s seam in the manufacture of products from fur waste. As input factors were taken: the number of stitches in 1 cm., Thread thickness, needle diameter. The features of the behavior of the strength model of this thread connection are revealed.

Improvement of the Process of Mechanical Dehydration of Five-Layer Wet Leather Semi-finished Products

To improve the process of mechanical dehydration of semi-finished wet leather products, a multilayer dehydration using felt materials – monshons was experimentally investigated. The process is conducted by vertical feed of semi-finished wet leather products on a base plate between rotating squeezing rollers. The D-optimal method of mathematical planning of the experiment and the Kano design matrix were used for conducting experiments. The multi-layer package consists of five layers of semi-finished wet leather products and two layers of moistureremoving materials between each layer, folded over the base plate. The studies were carried out in laboratory conditions on an experimental bench, taking into account the production parameters of processing. As a result of the study, mathematical dependences of the amount of removed moisture for each of five layers of semifinished wet leather product on the feed speed and the pressure of the squeezing rollers were derived. The analysis of the results showed that, with the existing parameters of mechanical dehydration, it was possible to simultaneously squeeze out moisture from five layers of the semi-finished leather product with a minimum pressure of the squeezing rollers and an average feed speed. The productivity of the technological process was more than five times higher in comparison with the productivity of similar roller machines. In the near future, this research methodology will be used to determine the technological factors affecting the extraction of excess moisture from a package consisting of ten semi-finished wet leather products and moisture-removing materials.

Optimization of conditions for esterification of thiodiacetic acid in urine using mathematical planning for biological monitoring

Introduction. To assess the impact of the toxicants vinyl chloride (VC) and 1,2-dichloroethane (DCE) on humans, personalized biomonitoring of thiodiacetic acid (TDAA) is of most significant importance. Determination of TDAA in urine was carried out using the method of gas chromatography-mass spectrometry GC-MS. Materials and methods. Sample preparation consists of the analyte’s esterification in a biological matrix with methyl alcohol (with 10% boron trifluoride), extraction of the derivative by liquid extraction with ethyl acetate. We used an Agilent 7890A gas chromatograph with an HP-5MS capillary column and a mass-selective detector. TDAA was identified in the form of a dimethyl ester on a mass chromatogram according to the retention time and the ratio of the intensities of the registered ions. Results. To determine the rational parameters of the sample preparation process for the determination of TDAA in urine studies were carried out under the method of planning the experiment, which makes it possible to obtain the most accurate mathematical description of the processes. Optimization of the conditions for esterification of TDAA was carried out using mathematical planning, varying the temperature, process time, and the nature of the catalyst (BF3 or H2SO4). The scheduling matrix included eight experiments; the degree of conversion of TDAA served as an optimization parameter. Interpretation of the model showed that temperature makes more contribution to the formation of the degree of conversion than the processing time. The nature of the catalyst does not affect the degree of conversion. Conclusion. A mathematical model developed for optimizing the conditions for sample preparation of the biomarker of exposure to VC (TDAA) in urine, showed the contribution of three factors (reaction temperature, reaction time, catalyst nature) to the conversion rate, of which the reaction temperature makes the greatest contribution to the choice of optimal esterification conditions. The nature of the catalyst (BF3 or H2SO4) does not affect the conversion rate.

The choice of excipients to obtain tablets based on the Primula denticulate Smith. Extract by wet granulation

Introduction. Herbal medicines are increasingly being used in the treatment of various diseases. Significant number of resources, high-level availability and the possibility of cultivation have provided high prospects of plant raw materials in the development of new herbal medicines. Primula denticulate Smith. is one of the most interesting medicinal plant raw materials source in modern medicine and pharmacy with the wide spectrum of pharmacotherapeutic action, that is mainly used only in traditional medicine. Thus, nowadays the development of new and effective medicines based on Primula denticulate Smith. in tablet dosage form is the topical task of pharmacy. The aim of the work. To study the influence of excipients on the pharmaco­technological parameters of tablets with Primula denticulate Smith, are obtained by wet granulation method and to substantiate the choosing of the best excipients by the method of mathematical planning of the experiment. Materials and Methods. It was used a self-prepared dense extract of Primula denticulate Smith. and excipients, which are complied with the requirements of State Pharmacopoeia of Ukraine in terms of pharmaco-technological quality parameters, for developing tablets. The hyper Greek-Latin square 4x4 was used to study the four qualitative factors. Results and Discussion. In the course of the experiment, it was determined the dependence of pharmaco­technological parameters (friability, resistance to crushing and disintegration of tablets) on type of excipients. It was selected excipients with the optimal pharmaco-technological parameters for further research the tablets quality. Conclusions. According to the method of mathematical planning of the experiment, it’s chosen the optimal excipients for obtaining tablets based on dense extract of Primula denticulate Smith. Considering the investigated pharmaco-technological properties (friability, resistance to crushing and disintegration of tablets) the qualitative composition of excipients for obtaining tablets by the method of wet granulation was determined: Avicel PH - 105 and MCC 101, croscarmellose sodium, colloidal anhydrous silicon dioxide, magnesium stearate and Prosolv 90.

Optimization of Ingredients upon Development of the Protective Polymeric Composite Coatings for the River and Sea Transport

It is proved that in order to increase the operational characteristics of parts of the river and sea transport, including their physical and mechanical properties, it is advisable to use the protective polymeric composite coatings. The effect of fillers on the flexural stresses of the developed epoxy composite was analyzed. The critical content of components was determined by the method of mathematical planning of the experiment: the synthesized powder mixture - 0.05 pts.wt., discrete fibers - 0.10 to 0.15 pts.wt. per 100 pts.wt. of epoxy oligomer ED-20. Introduction of such ingredients into the epoxy binder allows to increase the flexural stresses to σ f=77.4…78.6 MPa. The obtained results allow to create materials with improved values of physical and mechanical properties.