Influence Of Various Technological Factors Research Articles

The efficacy of complex solid dispersions of anthelmintics against experimental trichinellosis

The purpose of the research is to study the influence of various technological factors on obtaining of complex solid dispersions of anthelmintics with polyvinylpyrrolidone and licorice extract on anthelmintic efficacy in experimental trichinellosis of white mice.Materials and methods. The study of the nematodocidal activity of complex solid dispersions samples based on fenbendazole (FBZ), fenasal (FNS) and praziquantel (PZQ) with polyvinylpyrrolidone (PVP) and licorice extract (LE) obtained by mechanochemical technology at different ratios of components and different exposure times was carried out on 130 white mice experimentally infected with Trichinella spiralis in two experiments. On the 3rd day after infection, the animals were divided into experimental groups of 10 animals each. Samples of various complex solid dispersions of anthelmintics were administered intragastrically to the mice of the experimental groups at a dose of 2 mg/kg according to the active substance. FBZ substance was used as the basic drug at a dose of 2 mg/kg according to the active substance. Animals of the control groups did not receive the drugs. The animals were killed by decapitation on the 4th day after experimental drug samples administration, and the activity of the drugs was counted according to the results of helminthological necropsy of the intestine, the efficacy was calculated by the type of control test.Results and discussion. The efficacy of complex solid dispersions of FBZ and FNS with PVP polymer was higher in comparison with the activity of complexes with LE at the same duration of mechanochemical treatment in a roller mill. The FBZ activity decreased from 67.05 to 37.77% with a decrease in the duration of mechanochemical treatment from 24 h to 5 h and the efficacy of the FBZ : FNS complex with LE turned out to be almost at the level of the basic drug when treated for 1 h. The use of mechanochemical technology for obtaining of a solid dispersion of FBZ : FNS with PVP for targeted delivery makes it possible to increase the anthelmintic efficacy by 2.7 times compared with the activity of the FBZ substance, and with LE by 2.2 times. It was noted that complex solid dispersions of PBZ with PZQ have lower biological activity in comparison with compositions of FBZ with FNS.

Analysis of the Spectral Characteristics of the Responsivity of Diffusion <i>p-i-n</i> Photodiode Based on High Resistivity <p>p</p>-Si

This Taking into account the market need for highly responive silicon p-i-n photodiodes (PD) for detecting YAG-laser radiation (wavelength 1.064 μm), it was decided to investigate methods of increasing their responsivity, in particular, shifting the maximum of the spectral responsivity characteristic of the photodetector towards longer wavelengths, as well as to analyze the influence of various technological factors in its appearance. Research was conducted on silicon four-element p-i-n photodiodes with guard ring, manufactured by diffusion-planar and mesa technology. Single crystal p-type silicon with [111] orientation, resistivity of 13-21 kΩ and life time of minor charge carriers of 1.2-2 ms was used. It was found that when the reverse bias voltage increases, the maximum of the spectral characteristic shifts to longer wavelengths. This is caused by the expansion of the space charge region (SCR) with an increase in the bias voltage and, accordingly, an increase in the collection coefficient of charge carriers. When studying the spectral characteristic of samples with different resistivity, it was noticed that when the resistivity increases, the maximum of the spectral characteristic can be reached at a lower bias voltage. Because with a higher resistivity, the area of the SCR expands over the entire thickness of the substrate at a lower voltage. When expanding the space charge region to the maximum value, the responsivity level of the PD also reaches saturation. Accordingly, it makes no sense to use a bias voltage of the photodiode higher than the one at which the width of the SCR reaches the reverse side of the crystal. It is also seen that when the life time of minor charge carriers and silicon resistivity increases at the same bias voltage, the maximum of the spectral characteristic shifts to longer wavelengths. The maximum value of the spectral characteristic of 1.01-1.02 μm was reached. It was not possible to achieve a further shift, since the shape of the spectral characteristic of the sensitivity of photodetectors is primarily determined by the dependence of the collection coefficient of charge carrier on the wavelength, the maximum of which under normal conditions is at a wavelength of 0.8-0.9 μm. It is possible to achieve the maximum collection coefficient of charge carriers by optimizing the concentration of impurity in the p+- and n+- regions of the crystal, which allows minimizing the absorption of radiation in these regions. When using mesa technology, which minimizes the degradation of the resistivity of the material, no further shift of the maximum occurs, but the absolute value of responsivity increases compared to planar technology. For a wavelength of 1064 μm, a value of pulse responsivity of 0.5-0.53 A/W and 0.46-0.48 A/W was achieved for mesa- and planar PD, respectively (with a specific resistance of 20-21 kΩ), which is about 60% of the maximum value. It was also seen that a change in the depth of the PD diffusion layers can negatively affect the noise level. It was found that at a depth of n+-p-junction of 4.25 μm, the level of responsivity, at wavelengths below the maximum of the spectral characteristic, is the lowest, accordingly, the influence of background radiation noise on the level of the useful signal at this depth of p-n-junction is minimal.

Silicon four element p-i-n photodiode with improved characteristics

This article presents the results of the development of silicon coordinate p-i-n photodiodes (PD) with improved parameters. The technological possibilities of reducing the gaps between the responsive areas of multi-element PDs were studied. PDs with reduced gaps were modeled, samples were made according to the models, the parameters of the obtained PDs and the influence of various technological factors on their values were investigated. During research, it was established that the factor that limits the possibility of reducing the gaps is the insulation resistance between the responsive elements. The decrease in the insulation resistance between the PD elements was a consequence of the formation of inversion leakage channels at the Si-SiO2 interface, which is characteristic of high-resistance p-type silicon, the conductivity of which increased with a decrease in the width of the gaps. To increase the resistance of the gaps between the platforms and reduce the influence of inversion layers, it was decided to form regions of the restriction of the leakage channels between the REs – highly doped regions isotypic with the substrate material (p+-type). They will prevent the movement of current carriers that are generated in the inversion layers on the surface of the substrate. Four-element p-i-n photodiodes with 31 μm gaps between the sites were made. The proposed PD is not significantly inferior in parameters to analogues, but it is the sample with the smallest gaps between RE among photodiodes of the same type and size in the world market. The improvement of the insulation resistance between the REs made it possible to reduce the level of dark current of the PD by twice compared to serial products, with a slight decrease in responsivity due to the introduction of additional thermal operations into the technological route. In particular, the dark current density of the RE of experimental PDs was 40-80 nA/cm2, compared to 80-250 nA/cm2 for commercial samples. Impulse current monochromatic sensitivity at a wavelength of 1064 nm for experimental samples was 0.41-0.44 A/W, and for commercial ones - 0.45-0.48 A/W.

Effects of Concrete Compositions on the Elastic Modulus

The paper comments on the influence of various technological factors influencing the values of elastic modulus. Today, the composition of concrete combines the classic input components with the significant use of mixed cements, active admixtures and superplasticizers in order to achieve the required compressive strength of concrete and durability while reducing costs. On the other hand, the composition of these concretes has a negative impact on the elastic modulus which are significantly lower than the values derived from compressive strength in Eurocode 2. At the end of the article is a list of measures that are a prerequisite for obtaining the required concrete elastic modulus.

ESTIMATION OF ACCURACY OF COORDINATED SMALL DIAMETER HOLES WITH CUTTING TOOL DIRECTION

The dimensional analysis of the initial parameters of the coordinated dimensions of the holes is presented. Issues related to the assessment of the accuracy of the location of the surfaces of deep holes are considered. The influence of various technological factors on the magnitude of scattering of coordinated dimensions is studied. Experimental studies using experimental design methodology, which was used for sample preparations 45 steel, cast iron SCH15, aluminum alloys. Factors such as the cutting angle, the hardness of the workpiece, the cutting force and their effect on the diameter of the impression and its depth were studied. As a result of the experiments, a slight effect of the drilling force on the diameter and depth of the impression was found. However, it was found that the angle of the core leads to a directly proportional increase in the diameter of the imprint and inversely affects its depth. The hardness of the material has a more significant effect on the diameter of the imprint than on its depth. The total influence of controlled factors significantly affects the diameter of the imprint. Minimum core drilling angles are proposed for some materials. A mathematical model of the accuracy of machining coordinated holes is proposed on the basis of estimating the coefficients of the regression equation and finding the required mathematical models of the scattering fields of dimensions and deviations. As factors that vary during the drilling of coordinated holes, were taken: the length of the conductor sleeve, the departure of the tool, the hardness of the workpiece, the diameter of the tool. It is found that with increasing tool diameter and guide sleeve length decreases the amount of dimensional scattering from the base and positional deviations, and increasing tool departure and improving the physical and mechanical properties of the workpiece increase the size of the size scattering field from the base and positional deviation. An additional factor was introduced: the gap in the combination between the cutting tool and the conductor sleeve and obtained mathematical dependences of the influence of factors on dimensional accuracy when machining deep holes with the direction of the cutting tool. It is shown that the introduction of an additional factor - the gap, did not change the essence of the process of errors on small aggregate machines, and the change in diameters does not lead to a significant increase in scattering fields.

Technology for the Formation of Functional Coatings Based on Glass Microspheres

The technology for the formation of functional coatings from hollow glass microspheres by the self-organization method from aqueous-alcoholic suspensions is proposed. A monolayer with the closest (hexagonal) packing is shown to be formed on a solid (glass) substrate. The criterion for the ordering of a monolayer is proposed. The assessment of the influence of various technological factors on the monolayer formation rate and the degree of its ordering is given.

Analysis of the material flow in combined extrusion of steel bar stocks with a conical tool

In the manufacture of cylindrical products made of steel, representing a set of two thin-walled hollow cylindrical surfaces of different diameters with a bridge in the center, extrusion as a basic operation for their manufacture looks uncompromised. In order to reduce specific pressures during backward extrusion, various methods are used, from changing the working geometry of the tool and material temperatures to the variation of the friction coefficient using various lubricants. All this affects the nature of the flow and the degree of formation of the product’s walls. Therefore, the urgent task is to analyze the influence of technological parameters on the nature of the material flow during the combined extrusion of steel bar stocks with a conical tool. On the basis of finite element modeling, the article reveals the influence of various technological factors on the velocity of the material and its degree of flow into the working cavities of the die. The results can be useful in the selection of technological modes of manufacturing products similar in size by means of combined extrusion.

The Production Technology of the Ceramic Brick Soft Molding Based on Opoka-Like Rocks

The results of the scientific research and pilot tests on the production technology of soft molded ceramic bricks based on siliceous opoka-like rocks are presented. A description of soft-molded brick, which is distinguished by a huge variety of appearance and unusual design, which has earned recognition from architects and designers, is given. It is emphasized that the main limiting factor for the wide distribution of this type of brick is its high cost, due to the very small volumes of its production in Russia. It is indicated that the current situation poses a very difficult and urgent task for the wall ceramics industry - to establish the widespread production of soft-molded bricks, which in addition to the aesthetic properties will have the good operational properties. The opoka-like rocks’ characteristics and the results of studying their ceramic properties in relation to the technology of soft molding are given. The classification of the soft molded brick front surface types is presented for discussion. The main technological parameters of production, the relationship and the influence of various technological factors on the properties of the products obtained, as well as the mechanism for forming the structure of the calcined products are determined. A variable technological scheme for the production of soft molded ashlar brick has been developed. It is emphasized that the presented research results will be of interest to a wide circle of the molded ceramic bricks’ manufacturers and will help to establish the wide production of soft-molded bricks in Russia.

Complex processing of tin-lead dross into solders and ligatures

The use of industrial waste is one of the main problems of the modern economy. In Belarus, there is no primary metallurgical processing of natural raw materials, so the use of secondary materials and production waste is a very relevant and important task for the industry, given into account that the cost of metals extracted from secondary raw materials is several times less than the primary ones.One of the types of such raw materials is tin-lead dross (ash), which consists of tin and lead oxides with inclusions of the metal component beads. The most valuable element in dross is tin, the price of which is much higher than the cost of many non-ferrous metals. The aim of the work was to study the influence of various technological factors on the metallurgical output during the processing of tin-lead ash into solders and ligatures.In this regard the results of previous studies related to the extraction of tin and lead in the processing of secondary raw materials were summarized, and new data on technological methods for deeper metallurgical processing of dross (ash) were presented. This allowed them to develop options for obtaining high-quality solder type POS 61 and ligatures.

The ways of the defense products pricing system development

The article is devoted to one of the constantly discussed topics of development of the military-industrial complex – the directions of development of the pricing system for defense products [1, 2]. The main methods of pricing used in the military economy are highlighted. The ways of the pricing system development based on statistical and engineering methods of analysis of the influence of various technological factors are considered, the tendency of transition to the methods of «full» valuation of products with no connection to labor intensity is shown. The discounted cash flow method is considered as one of the methods of contract profitability estimation. The necessity of the creation of a modern effective pricing system based on an innovative-institutional approach is shown. It is indicated that the new pricing system will require the restructuring of organizational structures of enterprises with the inclusion of fundamentally new elements.

Assessing the Impact of Technological Factors on the Stability of Liposomes the Photosensitizer Phthalocyanine Series

Introduction.Liposomal technologies are widely used in medicine and cosmetology as a delivery system for diagnostic and medicinal products and biologically active substances. The undoubted practical importance at the stage of development of a liposomal preparation is represented by the characteristic and assessment of the sustainability of the obtained product, and special attention is paid to the study of the latter. Essentially, the methods for their preparation affect the stability of liposomes; therefore, the study of the influence of technological factors on the properties of the product at various stages of the preparation of liposomes is very important. This article is devoted to the study of the dependence of the quality of liposomes loaded with a phthalocyanine photosensitizer – thiosens, on the conditions of their production.Aim.Detection of the influence of various technological factors on the stability indicators of the liposomal form of the thiosens photosensitizer.Materials and methods.For this purpose, an analysis of the average size, polydispersity and zeta (ζ) potential of the liposomes of thiosens obtained at the stage of hydration of the lipid film, filtration of the liposomal dispersion, its extrusion, homogenization, ultrasonic treatment, and lyophilization was carried out.Results and discussion.During the preparation of a liposomal preparation, various changes in conditions can be made within the framework of the technological process. At each stage of obtaining a liposomal form, there are many critical points and parameters that must be strictly monitored and controlled. In the course of the work, the influence of technological factors on the stability of liposomal intermediate and finished products was assessed. The conditions of the most effective hydration with the formation of a stable dispersion of multilayer liposomes of thiosens and the optimal method of their grinding have been determined. It was also shown that liposomes formed after rehydration of the lyophilisate are more uniform in size and have the highest ζ-potential value in comparison with non-lyophilized liposomal dispersion.Conclusion.Using the example of a thiosens phthalocyanine photosensitizer liposomes, the influence of various technological factors on the stability of this nanostructure is shown, therefore, the characteristic and assessment of the sustainability of the resulting product according to 3 main indicators – vesicle size, polydispersity index, and ζ-potential are of undoubted practical importance.

Power parameters of the process of hardening of cylindrical parts by a toroidal roller by the method of surface plastic deformation

A theoretical study of the influence of various technological factors on the force parameters of the hardening process of a cylindrical blank by a method of surface plastic deformation was performed. Based on the approximate model of plastic deformation propagation, an engineering technique has been developed that allows one to specify the force regimes of the surface hardening process with a toroidal roller, taking into account the required degree of deformation of the hardened layer, taking into account the mutual influence of the geometric parameters of the workpiece, the deforming roller and the required depth of cold work. The results of the theoretical study are in good agreement with the known experimental data and can be used in the development of technological operations for hardening machine parts by rolling in rollers or balls.

A rational analytical model of flat rolling problem

In the mechanics of metal forming processes (particularly in strip rolling), it is important to determine the load on the machine tool that deforms the material into a new shape, as well as to compute the velocity field, strain rates and stresses in the deformation zone. Since no exact solutions are available for such problems, the perturbation method with respect to the Bingham number (which emerges from the analysis of the governing equations) is proposed for solving the rolling problem in viscoplastic deformation. We determine the neutral point position, as well as the equations for the discontinuity surfaces limiting the deformation zone. It is of interest to note that the most widely accepted theory of rolling predicts the so-called friction hill type of normal stress distribution in the roll gap. The analysis shows that this model could predict wave-like distribution of the roll pressure. The model also predicts the key parameters such as load and torque as functions of the rolling parameters. The theoretical results are numerically exemplified, and the influence of various technological factors on the rolling process is discussed.

Artificial Broken Stone Production for Industrial and Civil Engineering: Technological Parameters

The paper presents the results of investigation according to which the optimal fraction composition of clay concrete from Taskala gaize is found out. Its physical and mechanical properties are taken into account. The optimal fraction for crushed clay concrete is as follows: 5-10mm, 10-20mm and 20-40mm. The paper describes the influence of various technological factors on physical and mechanical properties of artificial crushed rock made from gaize. The role of preliminary thermal treatment of clay concrete particles and fractions is also looked into. According the results of the investigation the optimum thermal treatment temperature is stated. It's 200-3000°С for chert gaize and 400-4500°С for clay materials.

Regulation of the structure formation of ceramic masses of the system multimineral clay– kaolin-feldspar raw materials

Polymineral clay raw materials with absent sintering interval was selected as the main raw material for the synthesis of ceramic masses, production of ceramic clinker for various purposes using the plastic extrusion method.Kaolin and pegmatite from the Khmelivskyi deposit that may act as fluxing agents were selected as kaolinite-feldspar raw materials.Methods of directed structure formation regulation of ceramic masses based on polymineral clay raw materials using kaolinite-natural feldspar raw materials were investigated.Using mathematical planning, mathematical models of interaction and influence of various technological factors on the properties of experimental masses were developed. Using the correlation analysis method, the relationships in the system polymineral clay-kaolinite-natural feldspar raw materials were examined.Based on the ceramic mass 9 and 11 of the system polymineral clay-montmorillonite-substandard kaolin-pegmatite of the Khmelivskyi deposit, possibility to produce ceramic clinker by optimizing the chemical-mineralogical composition, and masses with a wide sintering interval was shown.

Laboratory Researches upon the thermal fatigue of the organs of machines in movement of rotation, in variable temperature mediums

The researches of durability in the exploitation of cast-iron rolls define experimentally an important chapter from the thermal fatigue of the organs of machines in the movement of rotation, in variable temperature mediums. The researches on the durability in exploitation of hot rolling mill rolls represent an important scientific and economical issue. This paper presents original experimental equipment by the help of which the durability of hot rolling mills can be studied. This experimental equipment permits the evaluation of exploitation durability for hot rolls by studying the thermal fatigue phenomenon which appears in the case of machine components. The exploitation durability is evaluated through thermal fatigue cycles up to crack point due to thermal fatigue for each condition and each type of studied material. The study represents a detailed approach of the influence of various technological factors on the durability in exploitation of rolling mill rolls made of different steel and pig iron grades and suggests solutions meant to increase the durability of the rolls in exploitation.

Acrylamide formation in traditional Czech leavened wheat-rye breads and wheat rolls

The main aim of our study was to collect the data on the acrylamide content in typical Czech leavened wheat-rye breads and wheat rolls, and to demonstrate the influence of various technological factors on its contents. We analysed several sets of industrially and laboratory baked breads to better understand the acrylamide formation. Following factors were tested: (i) the content of rye in respective bread formulae and (ii) the character of leavening procedure. We were, as well, monitoring for ten days the variability of acrylamide levels in bread baked by one bakery and, afterwards, we analysed the same type of bread baked in 12 bakeries. In the case of rolls, the influence of yeasts and vital gluten content in the dough were subjects of an assessment. The levels of acrylamide in a common type of the Czech bread baked in various bakeries were relatively low, ranging from 7 to 22 μg kg−1. The content of acrylamide was rather higher in breads prepared using a commercial starter (Lactobacilli) and yeasts than in bread prepared using natural rye sourdough only. A varying content of rye flour did not seem to have any impact on acrylamide levels. The ‘size dilution effect’ was observed when comparing the same type of bread with different weight. Since acrylamide is exclusively located in the bread crust, smaller loaves contained higher acrylamide content per kg. The contents of acrylamide in standard wheat bakery goods were very low, bellow 10 μg kg−1. No influence of varying content of added yeast or vital gluten was observed.

Oxidation of iron-ore pellets

The oxidation of magnetite in the roasting of iron-ore pellets is considered, with particular attention to the influence of various technological factors on the process. Laboratory data are used in optimizing the design and operational parameters of individual zones in conveyer roasting machines for the heat treatment of magnetite pellets.

Influence of coal preparation and coking conditions on coke reactivity

The influence of various technological factors on the high-temperature properties of coke is investigated. It is found that factors facilitating an orderly organic structure of the coke (fine grinding and compaction of the batch, increased conditioning of the coke, dry slaking, the introduction of lubricant additives in the batch) reduce the reactivity of the coke; by contrast, introducing coke fines, intermediate product, and red mud in the batch increases the reactivity.

Decomposition kinetics of supercooled austenite in moderate-carbon pipe steel

The mechanical properties of hot-rolled pump, compressor, and casing pipe made from moderate-carbon steel are largely determined by the content of various decomposition products of supercooled austenite (pearlite, excess ferrite, bainite) in the structure and by their morphology [1‐4]. The type and quantity of structural components depends on the composition of the steel (specifically, on the stability of the supercooled austenite), which, in turn, is affected by the rolling conditions, especially in the final stages of pipe production (the initial and final temperatures of reduction, the postdeformation cooling rate, etc.). In recent years, a group of dispersion-hardening Cr‐Mn‐Mo steels has been developed for the production of high-strength hotrolled pump and compressor pipe at OAO Sinarskii Trubnyi Zavod (SinTZ), in collaboration with the Russian Research Institute of the Pipe Industry and Ural State Technical University [4]. To this end, thermokinetic decomposition diagrams of supercooled austenite must be plotted both for the 37 E2e and 48 E2Aa steel traditionally used at SinTZ and for new steel. The influence of the austenitization temperature and hot plastic deformation on this diagram must be investigated. We consider the group of moderate-carbon pipe steels based on the compositions Mn‐Si and Mn‐Cr, microalloyed with vanadium (0.05‐0.10%), niobium (around 0.04%), and molybdenum (0.10‐0.20%). The thermokinetic decomposition diagrams of supercooled austenite are plotted from dilatometric, microstructural, and durometric data. To study the influence of various technological factors on the decomposition kinetics of supercooled austenite, 13 × 13 mm rods of the given steels are subjected to hot rolling on a laboratory mill, with 15% reduction. The laboratory conditions approximate the final operations in the production of hotrolled pipe. As is evident from Fig. 1, the decomposition of supercooled austenite in the given steels is characterized by clear separation of both decomposition stages and increased stability of the supercooled austenite in the region of diffusional transformations. It follows from direct measurements in the SinTZ shop [3] and from combined analysis of the microstructure and hard