Complete Factorial Experiment Research Articles

ИЗГОТОВЛЕНИЕ ПЕЛЛЕТ КОФЕИНА МЕТОДОМ ЭКСТРУЗИИ-СФЕРОНИЗАЦИИ ДЛЯ «КОКТЕЙЛЬНОЙ» ТЕСТ-СИСТЕМЫ

Cocktail" test systems are used for phenotyping the metabolic activity of human cytochrome P450 isoenzymes. The vast majority of "cocktails" for phenotyping include caffeine, based on data on the metabolism of which the activity of the CYP1A2 isoenzyme is determined. The use of pellets as a dosage form consisting of many particles for "cocktail" test systems makes it easy to change the composition and dosage of the test system depending on the needs of CYP research, and also provides easier acceptance of the test system by the patient in geriatric studies. Aim. Development of pellets containing caffeine for a "cocktail" test system using the methodology of a complete factor experiment. Materials and methods. Pellets containing caffeine (Shandong Xinhua Pharmaceutical Co., Ltd., China) were manufactured by extrusion-spheronization in the ESI 25 apparatus (Tofflon, China). The obtained pellets were subjected to technological tests in accordance with the GF of the Russian Federation XV. The quality of the pellets obtained and their dissolution profile were evaluated. Results and discussion. With the help of a complete factorial experiment, the optimal composition of pellets was selected, the optimal amount of granulating liquid was selected, and the parameters of the extrusion-spheronization process were worked out. Conclusion. As a result of the conducted research, the composition and technology of production of caffeine pellets for the cocktail test system were developed using a complete factorial experiment. A technological scheme for the production of pellets has been developed. Optimal conditions for humidification of the pellet mass were selected for the extrusion-spheronization technology.

RESEARCH OF THE DESTRUCTION CONDITIONS OF GLAZING OF ENCLOSING STRUCTURES UNDER THE CONDITIONS OF THERMAL INFLUENCE OF FIRE

The article presents the main results of mathematical modelling of the destruction of glazing of enclosing building structures with translucent elements under fire conditions. The authors analyse literature data on calculating the fire resistance of enclosing building structures with glazing. The results show that improving methods for predicting the fire resistance of glazing is relevant. Mathematical models for the numerical study of the behaviour of glazing under the thermal influence of the standard fire temperature regime are substantiated. Mathematical models of the heat transfer process involve using a non-stationary differential equation of heat conduction with boundary conditions of the third kind, accounting for the convective and radiant heat exchange between the air in the room with the fire and the glazing. As a criterion for the destruction of glazing under the influence of fire, the authors establish the temperature resistance parameter, which is determined based on the mechanical characteristics of the glass. The article highlights the relevant data on the study of temperature indicators and the mechanism of glazing failure, using mathematical modelling with well-founded mathematical models. It obtains the results of the thermal calculation by applying the finite difference method for solving the non-stationary differential equation of thermal conductivity. The methodology for determining the time of glazing failure under the influence of the standard temperature regime of a fire using the calculation parameters obtained based on well-founded mathematical models is substantiated. An analysis of the adequacy of the obtained calculation data was carried out by comparing them with the results of experimental studies using statistical criteria. As a result of the analysis, the authors confirmed the validity of the calculation data. A complete factorial experiment was conducted based on well-founded mathematical models, which revealed the regularities of the dependence of the parameters of thermomechanical processes in single-layer glass on its structural characteristics. The revealed regularities have the form of linear regression dependences of the destruction time on the thickness of the glazing and the maximum length of the glass panel without bars. Using the regularities of the dependence of the parameters of thermomechanical processes in single-layer glazing on its structural characteristics, the authors constructed reference tables for evaluating the fire resistance of enclosing structures with glazing. The research obtained new scientific data on the study of the behaviour of glazing of enclosing building structures under the thermal influence of fire through mathematical modelling, which is the basis for improving the methods of calculating the fire resistance of enclosing structures with translucent elements. Keywords: enclosing building structures, glazing, fire resistance limit, calculation method, glass heat resistance.

On-Target Deposition from Two Engine-Powered Sprayers in Medium-Foliage-Density Citrus Canopies

Spray penetration into citrus canopies is critical for adequate coverage and deposition to ensure effective pest control. However, mismatch of air assistance to target canopy characteristics can lead to unintended spraying losses through overpenetration. To evaluate the effect of air assistance on on-target deposition, two sprayers (surrogates for airflow rates) were used to apply a fluorescent tracer dye solution @ a target concentration of 300 ppm to 16 medium-foliage-density tree blocks in a commercial mandarin orchard. The complete factorial experiment in three replications, also designed for validating a model-based spray decision support tool, comprised two forward travel speeds (1.6 and 4.8 km/h), two disc-core nozzles (TeeJet® D3-25 and D6-45), and either one or two nozzle rows to obtain a wide range of application rates (496 to 9719 L/ha). Dye deposition significantly decreased with canopy depth (p =< 0.001) by nearly seven times across the 3.4 m wide canopies but was not significant over 1.2 to 2.2 m sampling height (p = 0.867). Deposition obtained with the low-airflow-rate sprayer was significantly greater (p =< 0.001) than that obtained with the high-airflow-rate sprayer over the dose range likely due to too much air pushing out spray droplets. This study underscores the importance of matching the air assistance of orchard sprayers to the target canopy.

Extraction, Characterisation and Evaluation of Antioxidant and Probiotic Growth Potential of Water-Soluble Polysaccharides from Ulva rigida Macroalgae.

Ulva rigida green macroalgae contain a variety of polysaccharides. A recent study investigated the optimum concentration and yield of polysaccharide extraction from oven-dried U. rigida biomass using a water-soluble polysaccharide extraction method that adhered to safety standards. This study utilised complete factorial experiments to examine the effects of varying factors on polysaccharide extraction. Results showed a positive correlation between increased levels of all factors and higher polysaccharide extraction yield. This study also found that the main factors and their interaction had a significant impact on the extracted polysaccharides from U. rigida. The highest polysaccharide content and yield were 9.5 mg/mL and 189 mg/g, respectively. Water-soluble polysaccharides demonstrated the presence of reducing sugar (8 mg/g), phenolics (0.69 mg/g) and flavonoids (1.42 mg/g) and exhibited antioxidant properties. Results revealed that freeze-dried polysaccharide powders were primarily composed of the monosaccharide rhamnose. Preliminary results on the effect of these powders on probiotics demonstrated that supplementation of polysaccharides from U. rigida promoted viable Lactobacillus rhamnosus ATCC 53103 growth during cultivation. This discovery has the potential to revolutionise the human food industry and promote the development of functional ingredients for novel and future food products, with numerous applications in the nutraceutical and pharmaceutical industries.

IMPACTO DEL USO DE DOLOMITA Y OLIVINO EN EL PROCESO DE GASIFICACIÓN DE DESECHOS SÓLIDOS DE NARANJA. CONTRASTE CON LA GASIFICACIÓN SIN EL USO DE CATALIZADORES

The industry processing of the orange generates high volumes of solid waste. This waste has been used to complement animal feeding and biochemical processes, but the gasification process has not valued its energy use. Gasification studies were carried out with air in a catalytic fluidized bed (using dolomite and olivine as catalysts in a secondary reactor, also varying the temperature of the secondary reactor and the catalyst mass) of the solid waste of orange, and the results are compared with those obtained in the gasification with non-catalytic air. In the processes, we use a design of a complete factorial experiment of 2k, valuing the influence of the independent variables and their interactions in the answers, using the software Design-Expert® and a grade of the significance of 95 %. The results demonstrate the qualities of the solid waste of orange in the energy use through the gasification process for the treatment of these residuals, obtaining a gas of low heating value. The use of catalysts also diminishes the yield of tars obtained in the gasification process, making dolomite more active than olivine. The better results of fluidized bed catalytic gasification of RSNs, in terms of gas heating value, gas yield, and low tar yield, are obtained when the secondary reactor operates at a temperature of 800 ºC and using 60 g of dolomite as a catalyst. Keywords: Orange waste, catalytic gasification, fluidized bed, dolomite, olivine

Assessing factors that increase dusky gopher frog larval performance in open‐canopy wetlands

AbstractAmphibians are declining worldwide, and research on their habitats and ecology is important for their conservation. The endangered dusky gopher frog (Rana sevosa) breeds exclusively in isolated, open canopy wetlands, usually with extensive herbaceous growth. Larvae of the dusky gopher frog have higher growth and survival under open canopy than under closed canopy conditions. The mechanisms whereby this occurs are poorly understood, however. In the summer of 2021 in Harrison County, Mississippi, USA, we conducted a complete factorial experiment in mesocosms to compare the relative influence of factors differing between open and closed canopy ponds on larvae. A heat and light treatment consisted of one third of tanks being exposed to full sunlight, one third of tanks being shaded with 70% shadecloth, and the final third being shaded with 70% shadecloth but heated to mimic the temperature of the full sun tanks. In addition, tanks received a closed canopy tree leaf litter mixture or an open canopy herbaceous vegetation mixture, and vertical vegetation‐like structure made of polypropylene rope or not. Cool shaded tanks and heated shaded tanks had identical survival to metamorphosis at 74.7% and produced frogs with an average mass of 2.21 g and 2.09 g, respectively, while tanks in full sunlight achieved significantly higher 93.4% survival to metamorphosis and an average mass of 2.64 g. The open canopy vegetation mixture yielded an average tank survival of 88.3% and mass of 2.94 g, compared to closed canopy vegetation tanks with a significantly lower survival of 73.5% and average mass of 1.61 g. Added structure had no effect on survival or mass. These results indicate that sunlight (not heat alone) and herbaceous plants are important in increasing dusky gopher frog survival and mass in open canopy conditions and suggest that management for these characteristics receive priority in captive‐rearing programs and habitat restoration.

Experimental studies of screw drill with frozen soil interaction

Introduction. The process of formation of wells in frozen soils is one of the complex processes of excavation. A drilling tool of a new geometric shape forms a well by brittle destruction of the rock. The purpose of the conducted experimental studies was to determine the effect on the energy intensity of the drilling process and on the well diameter coefficient of the angle of rotation of the radius of the screw blade, at which its increment occurs on the destructive part and the angle of inclination of the forming upper surface of the screw blade to the axis of rotation.Materials and methods. The article describes a methodology for conducting laboratory experiments to study the interaction of a drilling tool of a new geometric shape with frozen soils. The ranges of values of the studied factors are determined. The matrix of the complete factorial experiment is constructed.Results. As a result of laboratory experiments, the influence of the geometric parameters of the drilling tool on the energy intensity of the drilling process and on the well diameter coefficient was determined. The dependencies of the torque and the well diameter coefficient on the angle of rotation of the radius of the helical blade, at which its increment occurs on the destructive part, the angle of inclination of the forming upper surface of the helical blade to the axis of rotation and the angle of elevation of the middle helical line of the helical blade are established.Discussions and conclusion. It is established that the drilling tool carries out the formation of a well due to the brittle destruction of the well, which makes it possible to achieve more efficient drilling. And also the dependences of the rational values of the investigated geometric parameters of the drilling tool of a new geometric shape are determined.

ОЦЕНКА ВЛИЯНИЯ ТЕХНОЛОГИЧЕСКИХ РЕЖИМОВ ПЛАЗМЕННОГО НАНЕСЕНИЯ ПОКРЫТИЙ НА ТОЛЩИНУ ФОРМИРУЕМОГО СЛОЯ

Parts of technological machines, complexes and equipment used in many industries are subject to various types of mechanical wear, which leads to a significant decrease in their durability and an increase in maintenance and operating costs. Promising directions for improving the technologies of plasma application of wear-resistant coatings have been identified. Special attention was paid to the thickness of the functional layer, since when using plasma spraying methods, it has a significant impact on the quality of coatings. (Research purpose) The research purpose is developing mathematical models that make it possible to study the influence of the technological parameters of the plasma application of wear-resistant coatings on the thickness of the functional layer being formed. (Materials and methods) Samples made of 45 steel were used for experimental studies, on which a nickel-based powder PG-CP4 (PR-NH17CP4) was sprayed by plasma method. The current strength of the plasma torch arc, the spraying distance and the consumption of plasma-forming gas were adopted as the main technological modes of plasma spraying of coatings. The thickness of the formed coatings was measured on standardized equipment. Statistical processing of the obtained coating thickness values was carried out using a complete factor experiment using the Box-Wilson method. (Results and discussion). We have developed an experimental mathematical model of the technological process of plasma coating and demonstrated its operability. The criteria used to evaluate the variance of experiments, the adequacy and significance of the obtained regression equations are described. Using the Statistica program, a graphical interpretation of the studied dependencies was given. (Conclusions) Based on the mathematical planning of the experiment, models were obtained that make it possible to establish the relationship between the coating thickness and the specified technological parameters of the plasma spraying process. The results of the analysis of the presented analytical dependencies showed that the thickness of the coating is most influenced by the current strength of the plasma torch arc.

Analysis of Properties of Polymer Composites with Various Types of Fillers

The processes of structure formation of composite building materials (KSM) on different polymer binders are presented. It is shown that one of the most significant components of KSM are fillers, which help to improve their structural and operational characteristics. This work is devoted to the analysis of the results of an experimental study of the properties of epoxy composites with fillers having various elastic-plastic and strength properties. The research was carried out in three stages: at the first stage, studies were conducted aimed at assessing the influence of the nature of the filler on the curing processes of KSM; at the second, the influence of the type of filler and its quantitative content on the strength of composites was established, at the third, compositions were optimized using fillers with different indicators of grain composition and elastic-plastic properties. Powders of glass, dolomite, thermolite, and diatomite were considered as fillers at the first and second stages of the research, and powders of glass, ceramics, and chalk were considered at the second stage. The research at the third stage was carried out using mathematical methods of experiment planning with the construction of a planning matrix for a complete factor experiment and the determination of the values of the response functions relative to the encoded factors. The physico-mechanical properties, degree of curing, and chemical resistance of filled epoxy CCM have been established. On the basis of artificial neural networks, the maximum properties of the studied composites with fillers were determined. An assessment of structural properties based on rank correlation is also proposed. The results of the research can be used to predict the properties of KSM, as well as to clarify the extreme parameters of the properties. The dependences of changes in the properties of polymer composites on the surface characteristics, the dispersion of fillers and the degree of filling were established; preferred fillers for epoxy composites were determined; fillers were determined to assess the effect of elastic surface properties of composites, allowing to improve the strength and deformability of polymer composites; regression models were obtained based on a complete factorial experiment; an assessment of the «structural stability» of the studied composites using Pearson, Kendall, Spearman rank correlation; On the basis of artificial neural networks, the extreme properties of the studied composites with fillers were determined, neural networks.

Substantiation of the results of uneven leveling of heaps on the dryer conveyor

The article presents the results of finding the optimal combination of the selected factors having the minimum value of the indicator of uneven leveling of the pile on the dryer conveyor, an experiment was conducted, including 8 experiments, constituting a semi-replica of a complete factorial experiment of the type 2859+3, and a program of steep ascent along the response surface was performed. The experiment was carried out three times in a randomized order. In addition, an experiment planning matrix was built using a well-known technique. Based on the results of the experiment, regression coefficients were calculated and their statistical evaluation was carried out. To verify the adequacy of the presented experimental results, the calculated value of the Fisher criterion was determined by a polynomial of the first degree and compared with tabular values.

EVALUATION OF THE POSSIBILITY OF USING SPENT TURBINE OIL AS A LUBRICATING ADDITIVE IN DRILLING MUD

Link for citation: Lambin A.I., Averkina E.V., Erygina A.N., Averkin N.A. Evaluation of the possibility of using spent turbine oil as a lubricating additive in drilling mud. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 169-178. In Rus. The relevance. The consumption of lubricants and, as a result, the volume of used oils increases annually. As a result, large volumes of them are accumulated, which require standard methods of handling them. It is known that oils, including waste ones, are used as lubricating additives to drilling mud. The practice of recent years has shown the expediency of replacing lubricating additives with used lubricating oils, which would ensure the preservation of the main and the achievement of new properties. This article presents the results of a study of micelle-forming solutions under the influence of Na and K salts on their filtration and crust-forming properties. The main aim: evaluation of the possibility of using spent turbine oil in the drilling mud as a component of a lubricating additive, as well as its effect on the main parameters of the drilling mud; study of the effect of oil, ether and salt interaction on the filtration and crust-forming properties of drilling mud. Objects: spent turbine engine oils selected at the drilling site during the construction of the well. Methods. Drilling mud indicators were measured. Water, technical oil and ether were used to form micelles. The studies were carried out using the methodology of a complete factor experiment, in which the studied effects of salt in solutions were approximated in the form of first-order polynomials. Results. By comparing the first coefficients of the polynomial models, a significant effect of sodium chloride on the rheological and filtration properties of solutions and the stickiness of their filtration films was revealed. The effect of chlorides on a group of eight solutions in different oil fractions was statistically confirmed, for which the Student and Mann–Whitney criteria were used. The paper introduces the graphical interpretation of some approximations of the equations of the effect the solution ingredients interaction on the response value.

GASIFICACIÓN CATALÍTICA CON DOLOMITA Y OLIVINO EN LECHO FLUIDIZADO, DE RESIDUOS SÓLIDOS DE NARANJA. COMPARACIÓN CON LA GASIFICACIÓN NO CATALÍTICA

ABSTRACT: The industry processing of the orange generates high volumes of solid waste. This waste has been used to complement animal feeding and biochemical processes, but the gasification process has not valued its energy use. Gasification studies were carried out with air in a catalytic fluidized bed (using dolomite and olivine as catalysts in a secondary reactor, also varying the temperature of the secondary reactor and the catalyst mass) of the solid waste of orange, and the results are compared with those obtained in the gasification with non-catalytic air. In the processes, we use a design of a complete factorial experiment of 2k, valuing the influence of the independent variables and their interactions in the answers, using the software Design-Expert® and a grade of the significance of 95 %. The results demonstrate the qualities of the solid waste of orange in the energy use through the gasification process for the treatment of these residuals, obtaining a gas of low heating value. The use of catalysts also diminishes the yield of tars obtained in the gasification process, making dolomite more active than olivine. The better results of fluidized bed catalytic gasification of RSNs, in terms of gas heating value, gas yield, and low tar yield, are obtained when the secondary reactor operates at a temperature of 800 ºC and using 60 g of dolomite as a catalyst. Keywords: Orange waste, catalytic gasification, fluidized bed, dolomite, olivine

METHODOLOGY FOR MAKING EFFECTIVE MANAGEMENT DECISIONS TO ENSURE THE PHYSICAL SECURITY OF CRITICAL FACILITIES

The article discusses the issues of evaluating the effectiveness of the system of physical protection of critical facilities and the development of control solutions to ensure the necessary requirements for it. The relevance of the presented tasks is due to the increase in the number and types of violations, the improvement of the technical capabilities of violators, the complexity and variety of objects of protection. The presented methodology for making effective management decisions to ensure the physical security of critical facilities is a comprehensive study of physical protection systems. With the help of a simulation model, the probability of a safe state of the object on the specified routes of penetration of the intruder is estimated. The method of principal components revealed latent connections between routes, on the basis of which the decomposition of the complex task of managing the physical security of the object was carried out to obtain more reliable dependences of the probability of the safe state of the object on the parameters (characteristics and structure) physical protection systems. For each group of routes the probability of a safe state of the object of which is insufficient, a regression equation is constructed using a complete factorial experiment – a unique function of the object’s safety management. The analysis of the coefficients of the regression equations makes it possible to make effective management decisions to modernize the structure of the physical protection system, increasing its effectiveness to the required value.Obtaining management functions is the author’s methodology for making effective management decisions to ensure the physical security of critical facilities and determines the scientific novelty of the work.

DIAGNOSIS OF SYSTEMS UNDER CONDITIONS OF SMALL INITIAL DATA SAMPLING

Object of the study is to assess systems state in conditions of a small sample of initial data. Relevance of the problem is as follows. The functioning of a significant number of real objects takes place under conditions of poorly predicted changes in the values of environmental factors affecting system efficiency. The resulting heterogeneity of the results of objects experimental study and the environment of their functioning leads to reduction in sample size. At the same time, the standard requirements regarding the correspondence of the number of experiments and the number of coefficients of regression equation determining system state are not met. Purpose of the study is to develop methods for assessing systems state operating in a changing environment, in conditions of small sample of initial data. Tasks to be solved to achieve the goal: the first is the equivalent transformation of the set of observed initial data forming a passive experiment in aggregate into an active experiment, which corresponds to an orthogonal plan; the second is the construction of a truncated orthogonal representative sub-plan of the general orthogonal plan obtained as a result of solving the first problem. Research methods: statistical methods of experimental data processing, regression analysis, method for solving a triaxial boolean assignment problem. The results obtained: orthogonal representative subplan of the complete factorial experiment being formed makes it possible to calculate a truncated regression equation containing all the influencing factors and their interactions. Analysis of the coefficients of this equation by known methods makes it possible to cut off its insignificant elements.

Assessment of Processing Parameters of Pack Silicon Cementation onto P265GH Grade Steel.

The quantification of the single or combined variation of the process parameters specific to a thermochemical treatment is the key to a full factorial experiment and a first step in the development of computer-aided process engineering. Powdery solid media are frequently used in the practice of thermochemical treatments when the number of processed products is reduced, additional investments are not justified, or when there are no technological alternatives. The control of the process carried out in such powdery solid media involves both the control of the thermal and temporal parameters of the process on the layer growth kinetics and its phase composition, as well as the ratio of the powdery solid mixture mass percentage (active and neutral components, reaction activators, and components with the role of blocking the sintering tendency of the medium particles). In this paper, using the specific full factorial experiment (that is, a first-order complete factorial experiment (CFE)), the full model of the regression equation of the interactions between the specific process parameters of the silicide layer formation in a powdery solid media, applied to the low alloy P265GH steel grade and used in the petrochemical industry, were evaluated. Fe-ARMCO was chosen as the reference in the experimental research carried out.

Optimization of the Process of Obtaining a Charge of Lead-Antimony Alloy SSu3 by the Electroerosion Method in Distilled Water

The purpose of this work was to optimize the process of obtaining a charge of lead-antimony alloy SSu3 by the electroerosion method in distilled water according to the criterion of average particle size.Methods. At the experimental facility for the production of lead-antimony powders from conductive materials, the waste of the SSu3 alloy was dispersed in distilled water at a loading weight of 250 g. The following electrical parameters of the installation were used: voltage at the electrodes from 100–200 V; capacitance of capacitors 25–65 UF; pulse repetition frequency 25–50 Hz. The average particle size was studied using the Analysette 22 NanoTec plus laser particle size analyzer. The determination of the optimal parameters of the EED installation was carried out by setting up a complete factorial experiment (PFE) on the average particle size of the obtained electroerosive materials. The parameters of the EED installation operation were selected as factors: the voltage at the electrodes, the capacitance of the discharge capacitors and the pulse repetition rate.Results. According to the conducted series of experiments, the results of which are presented in the table, the limiting values of the optimization parameter y (the average size of electroerosive particles) were determined, which amounted to: 44 microns with a capacity of 65.5 UF discharge capacitors, a voltage at the electrodes of 200 V, a pulse repetition frequency of 75 Hz.The conducted studies have shown that by the method of electroerosive dispersion of SSu3 alloy waste in distilled water, it is possible to obtain an alloy powder with a uniform distribution of alloying elements.Conclusion. Optimization of the process of obtaining the charge of lead-antimony alloy SSu3 by the electroerosion method in distilled water according to the criterion of the average particle size was carried out. The results obtained can be used by enterprises of the industrial sector for the production of lead-antimony powder.

Statistical processing of a small sample of raw data using artificial orthogonalisation technology

This paper addresses the task to devise a statistical estimation procedure in an event where the volume of the array of initial data used in processing is insufficient to correctly determine the parameters of the response function. The object of research is the technology of statistical processing of a small sample of data. The subject of the study is the methods of statistical estimation under conditions of a small sample of initial data. The main direction is to devise a special procedure for statistical processing of a small sample of initial data, which provides a correct statistical estimation of the parameters of the response function. The method for solving the problem is the selection of the most representative orthogonal replica-like subplan from the plan of a complete factorial experiment obtained by artificially orthogonalizing the results of a passive experiment. The necessity and expediency of the proposed procedure is a consequence of the unpredictability and uneven distribution of points in the phase space of coordinates. The result of the implementation of the corresponding procedure is a truncated orthogonal plan of the full factorial experiment, which provides the possibility of independent estimation of all coefficients of the regression polynomial describing the response function. Under conditions of a severe shortage of the number of measurements, the procedure makes it possible to isolate a representative orthogonal replica from the resulting plan of a complete factorial experiment. Using this subplan of the full factorial experiment plan makes it possible to evaluate all the coefficients of the regression polynomial that describes the desired response function. The corresponding computational procedure is based on solving the triaxial Boolean assignment problem

ГРАФОАНАЛИТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ШЕРОХОВАТОСТИ ПЕРЕДНЕЙ ВИНТОВОЙ ПОВЕРХНОСТИ РЕЖУЩЕГО ИНСТРУМЕНТА

The paper deals with a method for grapho-analytical modeling of micro-roughness (surface roughness) formed on the helical front surface of a cutting tool during its manufacture or resharpening using CNC grinding machines and grinding wheels with a simple shape of the generative surface.
 A simulation model of roughness on the formed front surface is presented, and a calculation scheme for determining its value is made. Based on the statistical results of the formed technological 3D models of helical front surfaces, the resulting equations of complete factorial experiments are presented, taking into account the combined influence of factors.
 Graphs of the normal distribution of the roughness parameter and the parameter of the grinding wheel installation affecting it are given.
 It is shown that an important result of modeling is the definition of the micro-roughness direction, and a recommendation is given to indicate the directions of micro-roughness in the drawings of the cutting tool in order to mearure roughness taking into account the requirements of regulatory and technical documentation.

Исследование влияния температурного режима пожара на эффективность вспучивающегося огнезащитного покрытия, предназначенного для огнезащиты стальных конструкций

Introduction. The usage of intumescent coating (hereinafter referred to as IC) is justified by the development of a fire protection project, taking into account the data on its fire protection efficiency, estimated under the influence of standard temperature conditions, the usage of which can lead to overestimating the fire resistance margin in the project or underestimating the thermal impact on the steel building structures with IC fire protection in conditions of a real fire. Aims and purposes. The purpose of the study is to evaluate the effect of fire temperature conditions on the effectiveness of IC. To achieve this goal, the following tasks were carried out: a temperature mode of fire in a building under different fire loads by the example of a warehouse building was estimated; experiments to estimate the influence of different heat fluxes, reduced thickness of metal and IC thickness on its effectiveness by the full factor experiment of the type 2 were conducted. Methods. To mathematically simulate real temperature fires, the Fire Dynamics Simulator (FDS) software package, which implements a field (differential) mathematical model, was used. To study the effect of the obtained fire temperature regimes on the effectiveness of IC, experiments were carried out according to the plan of a complete factor experiment type 2. The test specimens were carbon steel metal plates with dimensions of 100 × 100 mm with reduced thickness of 3 and 4.5 mm and painted with 0.25 and 0.5 mm organic-based single-component IC. A radiant heat flux panel with a radiant heat flux density of 10 to 50 kW/m2 was used to assess the effects of heat flux. Results and discussion. In the course of numerical experiments in the FDS software package, it was found that the thermal impact on steel building structures during a fire can differ significantly from the standard temperature regime, both upwards and downwards. The results of the experiment showed that the heating time of the test samples had the greatest influence of the actors under consideration (the value of the heat flux, the reduced thickness of the metal, the thickness of IC) had the value of the heat flux, as the largest absolute value of the regression equation was obtained. Conclusion. The assumption of possible underestimation of the thermal effect under “standard” temperature conditions on the fire resistance of steel building structures with IC fire protection was confirmed by the tests.

A Note on Early Termination in the 2^(k-p) Designs

A complete factorial experiment can resolve problems that occur in experiments that to determine suitable tolerances for the factors in a manufacturing process. Two-level fractional factorial designs have been widely used to investigate the effect of factors in which several factors are involved. In many circumstances, the experiment may be stopped before all the points have been run. This article argues that one should not arrange the points of the experiment in random order. Instead, one should consider adjusting the run order to protect against the risk of early termination, that is, a systematic run order should be carefully applied to the case. In this article, we will use semi-folding design as examples to illustrate the idea of how to take advantage of the sequential run order.