bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construction of a mathematical model of the film absorber for sulfating two-component mixtures of organic substances
Authors: Dzevochko Oleksandr , Podustov Mykhaylo , Dzevochko Alona , Panasenko Vladimir 
Published: December 2021

The processes that occur in film absorbers during the sulfation of two-component mixtures of organic substances are quite complex and require mathematical modeling. This paper reports the construction of a mathematical model that makes it possible to adequately describe the process of sulfation involving gaseous sulfur trioxide in the production of surfactants. Based on the model, it became possible to investigate this process for higher alcohols of fractions С12–С14 and monoethanolamides of higher fatty acids of coconut oil.
The data are given on the comparison of mathematical modeling results based on the mathematical model built with known experimental data and results of alternative mathematical modeling for different ratios of the length of the reaction pipe to its diameter (l/d). It is shown that the error in comparing the experimental data was 4.8–9.6 % at l l/d=29; 1.1–8.7 % at l/d=70; 3.9–12.3 % at l/d=144. The error in comparing known results of alternative mathematical modeling was, respectively, 6.3–7.2 %, 0.1–6.5 %, 0–1.0 %. These results were obtained for the molar ratio in the range of 1.0–1.15 and the SO3 concentration in the stream of 4.0–6.0 %.
Such findings suggest that the established dependences of the basic parameters for the sulfation process are adequate in terms of the absorber length and its radial direction. Therefore, the mathematical model built does hold within the considered ranges of input variables. Consequently, it could be used in the theoretical study of the process of sulfation of two-component mixtures of organic substances by gaseous sulfur trioxide in a film absorber with a downward flow of phases. The results obtained could be used in practice, in particular in the manufacture of high-quality products for the cosmetic industry.
Determining energetic characteristics and selecting environmentally friendly components for solid rocket propellants at the early stages of design
Authors: Kositsyna Olena , Varlan Kostiantyn , Dron Mykola , Kulyk Oleksii 
Published: December 2021

This paper has investigated the possibility to theoretically calculate a value of the specific impulse for highly energetic compositions using only two parameters – the heat of the reaction and the number of moles of gaseous decomposition reaction products. Specific impulse is one of the most important energetic characteristics of rocket propellant. It demonstrates the level of achieving the value of engine thrust and propellant utilization efficiency. Determining the specific impulse experimentally is a complex task that requires meeting special conditions. For the stage of synthesis of new promising components, the comparative analysis of energetic characteristics, forecasting the value of specific impulse, especially relevant are calculation methods. Most of these methods were first developed to determine the energetic characteristics of explosives. Since explosives and rocket propellants in many cases have similar energy content and similar chemical composition, some estimation methods can be used to assess the specific impulse of solid rocket propellant.
The specific impulse has been calculated for 45 compositions based on environmentally friendly oxidizers (ammonium dinitramide, hydrazinium nitroformate, hexanitrohexaazaisowurtzitane) and polymer binders polybutadiene with terminal hydroxyl groups, glycidylazide polymer, poly-3-nitratomethyl-3-methyloxetane). It was established that the estimation data obtained correlate well with literary data. Deviation of the derived values of the specific impulse from those reported in the literature is from 0.4 % to 1.8 %. The calculation results could be used for preliminary forecasting of energetic characteristics for highly energetic compositions, selecting the most promising components, as well as their ratios.
Comparative analysis of methods for prediction continuous numerical features on big datasets
Authors: Kinshakov Eduard , Parfenenko Yuliia , Shendryk Vira 
Published: December 2021

The object of research is the process of choosing a method for predicting continuous numerical features on big datasets. The importance of the study is due to the fact that today in various subject areas it is necessary to solve the problem of predicting performance indicators based on data collected from different sources and presented in different formats, which is the task of big data analysis. To solve the problem, the methods of statistical analysis were considered, namely multiple linear regression, decision trees and a random forest. An array of extensive data was built without specifying the subject area, its preliminary processing, analysis was carried out to establish the correlation between the features. The processing of the big data array was carried out using the technology of parallel computing by means of the Dask library of the Python language. Since working with big data requires significant computing resources, this approach does not require the use of powerful computer technology. Prediction models were built using multiple linear regression methods, decision trees and a random forest, visualization of the prediction results and analysis of the reliability of the constructed models. Based on the results of calculating the prediction error, it was found that the greatest prediction accuracy among the considered methods is the random forest method. When applying this method, the prediction accuracy for a dataset of numerical features was approximately 97 %, which indicates a high reliability of the constructed model. Thus, it is possible to conclude that the random forest method is suitable for solving prediction problems using large data sets, it can be used for datasets with a large number of features and is not sensitive to data scaling. The developed software application in Python can be used to predict numerical features from different subject areas, the prediction results are imported into a text file.
Application of in-plastic catalysis for extraction of hard-to-recover hydrocarbons
Authors: Zezekalo Ivan , Kovalenko Viktor , Lartseva Iryna , Dubyna Olexandr 
Published: December 2021

The object of research is the catalytic effect (hydrocracking) for the production of hard-to-recover hydrocarbons, the subject of the study is the change in the physicochemical properties of hydrocarbons by partial gasification, and the lightening of the fractional composition of hydrocarbons. One of the most problematic areas is the lack of studies of the catalytic effect on hard-to-recover hydrocarbons in reservoir conditions. Although processes such as catalytic cracking, reforming, isomerization, aromatization and alkylation of hydrocarbons are known and used in petroleum refining.
The research used the methods of scientific knowledge – experiment and measurement. In the course of laboratory work, an effective catalyst was developed, the effect of temperature on the fractional composition and physicochemical properties of oil, oil products and gas condensate was investigated. To simulate formation conditions, hermetic metal retorts were used, in which oil and gas condensate samples were subjected to different temperature regimes. In the process of testing cores saturated with gas condensate, the dependence of filtration on physical parameters – temperature and pressure, fractional composition, specific gravity and viscosity was studied.
Laboratory studies have shown a decrease in density and viscosity of hydrocarbons, an increase in core permeability. The effect of catalysis on oil made it possible to increase the volume of light ends distillation from 30 to 60 %, for gas condensate – up to 50 %, which confirms the effectiveness of the method of catalysis of hard-to-recover hydrocarbons. This is due to the fact that the correct formulation and solution of the problem provided adequate results. In contrast to the existing processes of hydrocracking of petroleum products, the proposed method allows you to extract heavy and low-mobile hydrocarbons in reservoir conditions at lower temperatures of 120–150 °С. At the same time, the technology for catalytic hydrogenation of hard-to-recover hydrocarbons will be similar to a typical treatment of a formation with an acid or surfactants. This will make it possible to intensify the commercial reserves of hydrocarbons in the fields that are now classified as hard-to-recover and which account for more than 50 %.
Increase of dynamic stability of a basis at operation of the compressor equipment of the Abazіvka unit of complex gas preparation
Authors: Mykhailovska Olena , Zotsenko Mykola 
Published: December 2021

The object of research is the basis of the compressor equipment of the complex gas treatment plant at the Abazivka field and the strengthening of the base soils with soil-cement elements, which are proposed to be arranged with the use of drilling technology. The research area is located on the territory of the current Abazivka Integrated Gas Preparation, near the village of Bugaivka, Poltava region, Ukraine. Abazivka Integrated Gas Preparation receives products from wells in Abazivka and Sementsivske deposits. It is proposed to carry out the reconstruction of Integrated Gas Preparation, which includes strengthening the foundation of the compressor model C1004-JGT/2-1 manufactured by «Propak» (Alberta, Canada). The amplitudes of oscillations of the compressor foundation were determined at a speed of 1400 rpm at the appropriate site with geological conditions. The magnitudes of oscillations and subsidence of the compressor foundation of the Abazivka complex of complex gas treatment were investigated experimentally. When determining the amplitudes of oscillations of the compressor foundations, only the amplitudes of oscillations in the direction parallel to the sliding of the pistons were calculated, and the influence of the vertical component of the perturbing forces was not taken into account. It is established that the amplitude of horizontal-rotational oscillations of the upper face of the compressor foundation relative to the horizontal axis exceeds the maximum allowable. It is substantiated that soil cement is a sufficiently strong and waterproof material that can be used to strengthen the base during the construction of equipment foundations. The possibility of application of the technology of application of soil-cement piles, made by brown-mixing technology for strengthening the base under the foundation of the compressor, is described and investigated. It is proposed to reinforce the base with rows of soil-cement elements, which will increase the modulus of deformation of the base, which is represented by loam, light to 14.3 MPa. In the case of strengthening the base, the amplitude of horizontal-rotational oscillations of the upper face of the compressor foundation is much less than the maximum allowable 0.1 mm. The subsidence of the foundation at reinforcement of the base, which does not exceed the maximum allowable value, is determined. Soil-cement elements are proposed to be arranged according to the drilling technology.
Cooling process optimization during hardening steel in water polyalkylene glycol solutions
Authors: Kobasko Nikolai 
Published: December 2021

Objects of investigations are water solutions of polyalkylene glycol (PAG) which are used as the quenchants in the heat-treating industry. They are tested by standard cylindrical probe made of Inconel 600 material. The main and not solved yet is the problem of transition from data achieved for standard probe to data suitable for any form and size of real steel part. It opens possibility to make predictable calculations. Taken this into account, it has been investigated water solutions of PAG of different concentration. It is underlined that cooling intensity of quenchant can be evaluated by Kondratiev number Kn. The mentioned number Kn varies within 0≤Kn≤1 when generalized Biot Biv number varies within 0≤Biv≤∞. As a main achievement of investigation is established correlation between standard Kn number and Kn number of real steel part. In many cases, when film boiling is absent, the established correlation is a linear function. It allows optimizing quenching processes: obtain high surface compressive residual stresses, save alloy elements and improve environment condition. All of this is achieved by tolerating chemical composition of steel with size and form of quenched object as it is proposed by UA Patent No. 114174. Also, the number Kn allows interruption of quench process when surface compressive residual stresses are at their maximum value that essentially improves the quality of steel components. Moreover, interrupted cooling prevents quench crack formation, decreases distortion of quenched steel parts. The results of investigations can be used by engineers in the heat-treating industry and scientists for further research.
Local cellular immune response in chronic periodontitis
Authors: Mudrov V. P. , Davidova N. V. , Mishina T. E. , Kazakov S. P. 
Published: December 2021

Microflora of the oral cavity forms a biofilm that induces response of immune system at the mucous membranes. Transition to periodontal lesion is provided by certain classes of resident mucosal immune cells and inflammatory/immune cells migrating to the periodont. In periodontal diseases, Th1, Th2, Th17, Treg are detected. T regulatory cells (Tregs) are proven to comprise the main anti-inflammatory cell population. Th17 cells and Treg cells play an important role in osteoclast differentiation. IL-17 secreted by Th17 cells affects osteoclastogenesis and may induce macrophages to enhance the local inflammatory response. In this regard, the aim of our work was to identify the local immune cells in oral cavity which are associated with severity of chronic generalized periodontitis. The oral cavity cells from 58 persons aged 38-65 years of both sexes in their mature age with a diagnosis of «chronic periodontitis» were examined by means of flow cytofluorometry. When determining levels of CD64+CD16+CD14- neutrophils in the patients with periodontitis of different severity, a statistically significant increase of this cell population was revealed upon development of this disease. In mild cases of periodontitis, a significant increase of relative CD64+CD16+CD14- neutrophil contents was revealed (Me = 36.16%, p < 0.05) compared to the control group (Me = 7.7%, Q0.25 = 2.4%, Q0.75 = 12%). When assessing relative numbers of CD14+ monocytes in periodontitis of various severity, we revealed a significant increase in the number of these cells in severe cases. When studying levels of regulatory T lymphocytes (CD4+CD25+CD127low) in periodontitis of different severity, we revealed significantly decreased amounts of this cell population during development of the disease. In mild cases of periodontitis, a decreased level of CD4+CD25+CD127low cells (p < 0.05, Me = 1356 cells/ml) was revealed, as compared with control group (Me = 10666 cells/ml). Although the concentration of CD4+CD25+CD127low (Me = 4709 cells/ml) in the patients with moderate periodontitis was higher than the values in milder cases, the range of the main values was comparable and lower, than in control group. In severe periodontitis, a significantly decreased concentration of regulatory T lymphocytes was revealed (Me = 2637 cells/ml). These results confirm the anti-inflammatory regulatory function of Tregs. Understanding the osteo-immune mechanisms of bone remodeling control will help to understand the pathophysiology of accelerated bone loss observed in severe chronic periodontitis.
Technical – Material Basis of Agro Tourism Support of Touristic Potential in Romania
Authors: CALINA Jenica , CALINA Aurel 
Published: December 2021

This paper analyses the indicators characterizing the accommodation capacity to obtain an overview on the technical- material basis of agro-tourism, alongside statistical indicators presenting the dimension of the touristic circulation in the Romanian rural area. In agro-touristic boarding houses, places offered to tourists increased in year 2009, as compared to 1999, 20.04 times, and the accommodation capacity increased 9.82 times.
In respect to the touristic capacity, the specific tendency of increase of the accommodation indexes dislocated, the agro-touristic boarding houses representing accommodation units that net usage index registers increases.
Research Regarding the Flow Rate and Pressure Variation for the Nozzles Mounted on the Eep-600m Spraying Machine
Authors: DROCAS Ioan , MARIAN Ovidiu , RANTA Ovidiu , STANILA Sorin , MUNTEAN Mircea , MOLNAR Adrian 
Published: December 2021

Reduced environmental pollution and ensuring fair treatment in crops can be achieved through constructive and functional upgrading of spraying machines.
The paper studies the variation of the nozzle flow, liquid pressure and uniformity of distribution for the EEP-600M machine.
The experimental results have shown changes in the functional parameters of the nozzle (flow and pressure) depending on the nozzle position on the ramp section. The way of connecting the hoses leading the solution to the ramp and the number of nozzles per segment can influence the uniformity of distribution of the solution.
Compare to Different Green Roughage Nutritional Value and Productivity on Southern Transdanubian Region
Authors: HOFFMANN Richárd , KOVÁCS Bernadett 
Published: December 2021

Roughage produced on crop fields is basic roughage in cattle’s nutrition. If we do not have enough grassland, than we have to find alternatives in the vegetation period which are able to give cheap and natural roughage. Nowadays semi-intensive milk and beef production, as well as heifer rearing on the small or medium size farms, there is a demand for green fodder based diet during the vegetation period instead of monodietical or grass feeding.
To achieve a more efficient system of green feeding it is necessary to introduce new species in ruminant nutrition as green fodder, which nutritional value has not been exactly evaluated yet. The objective of this paper compare to different green roughage mixtures could be used in the green feeding system. The next mixtures were examined: triticale & vetch (Vicia pannonica), winter barley (Hordeum vulgare)& vetch. The yield and nutrition content were determined for the whole mixtures and for each mixture component.
There was significant difference among the roughage mixtures. Triticale mixed with pannon vetch (TR&PV) gave significantly higher yield (36.6 t/ha) than the two mixtures with winter barleys (29.7 t/ha and 31,4 t/ha). The crude protein contents was the lowest in case of TR&PV (168 g/kg DM), the highest crude protein was found in case of barley mixed with pannon vetch (182 g/kg DM). The nutritional value found in case of pannon vetch with barley and pannon vetch with triticale highly differs from those of other green fodders mentioned by Schmidt et al (2000).
Research in Vegetation House on the Possible Use of Microorganisms in Bioremediation of Soils Contaminated with Crude Oil
Authors: PARVAN Lavinia , CARABIS Delia , TOTI M. 
Published: December 2021

Within the remediation methods experimented all over the world, the bioremediation in situ based on the activity of microorganisms to use the oil hydrocarbons as carbon and energy source, is considered the most effective, especially, because it does not involves the severe and irreversible disruption of structure and, implicitly, the pedogenic characteristics of affected soil and its cost is relatively low.
The microorganisms represent probably the most important component of terrestrial ecosystems, which by their highly diverse physiological activity are the basis of the functions creating soil fertility.
The N100P100K100 fertilization treatment and application of bacterial inoculum proved the most effective so far.
Characterization of a Typical Districambosol Soil from the Gutai Mountains – North of Romania
Authors: VOSGAN Zorica , VIDICAN Roxana , JELEA Stela , MARIAN Monica , MIHALESCU Lucia , MARE ROSCA Oana 
Published: December 2021

This study has been carried out in a pastoral area of Maramures County, on the south-estic slope of Gutai Mountain, where it is situated the pasture for the ovines and caprines of the inhabitants of the surrounding villages.
It has been identified in this area a districambosol soil characterized by high acidity, a composition rich in nitrogen and humus due to slow humification, moderate reserves of potassium and phosphor. The assay indicates a clayey composition except for the At horizon which has a composition predominant in fine sand.
In order to increase the value of the pasture, improvement and maintainance works should be performed.
Results Regardind the Ochratoxin a Analysis in Feed Formulas
Authors: FEIER Dana , TOFANA Maria 
Published: December 2021

. Ochratoxin A is a toxic metabolite produced by Aspergillus and Penicillium spp. Among the metabolites of type A, Ochraceus is considered as being one of the main producers. Ochratoxin A is the main mycotoxin from the ochratoxines group, and it seems to be the only one with a toxicological significance (Derache R., Paris).
Ochratoxin A has been proven to be nephrotoxic, hepatotoxic, teratogenic, immunotoxic, mutagenic and carcinogenic in some animal species and possibly carcinogenic for humans. Therefore, this study tried to determine the levels of Ochratoxin A by ELISA- screening test from samples of feed formulas for pigs and poultry.
The quantities of Ochratoxin A obtained in the study are below the permissible limit provided in the Commission Recommendation no. 576 of 17 Augus 2006.
Quality Characteristics and Standards for Sunflower Oil from Arad Agricultural Area
Authors: MUREŞAN Claudia , DICU Anca Mihaela , CIUTINA Virgil , CHAMBRE Dorina , URSACHI Claudiu 
Published: December 2021

The purpose of this study was to determine the unsaturated fatty acid compounds of studied oils, physico-chemical parameters, and the behavior of the four oil types during oxidation and heating.
This is a part of a large study effectuated on Carnia sunflower hybrids, PR64H91, PR65A22 and PR64H45 obtained through cold pressing. We followed the evolution of the UV absorption correlated with the peroxide value. The peroxide value has been presented an increased value in the first 12 heating hours, but after this period of time, it has been decreased due to the high temperature instability of the early formed hydro-peroxides. The absorbance between 220-230 nm and the specific absorbance on 232 and 270 nm (characteristic of the conjugated dienes and trienes) have increased along the experiment period. The results were compared with those from regular sunflower oil.