Results Of Mathematical Calculations Research Articles

INTERRELATION OF BIOLOGICAL ACTIVITY AND CALCULATED PARAMETERS OF NITRILSILANES AND NITRILSILOXANES

The processes of oil production, transport, refining are time-bound, which is fraught with sludge and storage, which is the cause of microbiological corrosion. The geometric, electronic and energy parameters of previously synthesized organosilicon nitriles and the manifestation of their antimicrobial activity are studied, and some regularities of their physicochemical properties are established. It was found that heteroatomic compounds containing silicon atoms in their composition have a high and effective fungicidal activity, inhibiting the growth of fungi and plants, as well as minimal toxicity. It has been established that the effect of the studied compounds can last up to several weeks, in contrast to the currently used drugs of biological action during the storage and transportation of petroleum oils. The results of the physicochemical parameters of a number of nitrilesilanes and nitrilesiloxanes calculated by the DFT method with the B3LYP/6-31G(d,p) functional are presented. The studied compounds are highly reactive, and in this work the biological activities of a number of organosilicon nitriles have been experimentally established. Based on the calculated and experimental data obtained, the relationship between the energies of the boundary molecular orbitals (depending on the electronic structure) and the antimicrobial properties of the presented nitrile silanes and nitrile siloxanes were established. It has been shown that a number of studied organosilicon compounds, especially nitrile siloxanes, are superior in bactericidal activity to the biocide sodium pentachlorophenolate. When compiling a 3D function graph, the average deviation of the results of mathematical calculations from the results of a biological experiment was a maximum of 23%. It has been established that the most effective of the given compounds of a number of organosilicon nitrile silanes and nitrile siloxanes can be widely used in industry and can be recommended as biocidal additives for lubricating oils and other lubricating and cutting fluids and materials.

Evaluating the linear accelerator accuracy: Integrating Winston-Lutz measurement method and mathematical calculations

The Electronic Portal Image Device (EPID) is commonly used to evaluate the difference between the mechanical and radiation centers of a linear accelerator; however, the gantry and EPID are limited in some non-coplanar angles due to collisions with the treatment couch. This study aimed to compare the results of mathematical calculations and actual measurements to evaluate the feasibility of assessing the differences in the mechanical and radiation field isocenters. A 20 mm Stereotactic Circular Collimator was mounted on the head of the linear accelerator (LINAC), and an Elekta 8 mm ball-bearing (BB) was placed on the couch, following the Winston-Lutz (WL) measurement method. Measurements were taken with varying gantry and couch positions, and Image J software was used to analyze the images. Two regions with a difference of more than 0.1 mm were identified. The first region was between T270 and T330, with gantry angles ranging from G120 to G160. The second region was between T280 and T340, with gantry angles ranging from G290 to G330, and the two regions showed a symmetric diagonal relationship in terms of the gantry angles. The paired sample t-test showed no significant difference between the actual measurements and the calculated results (p-value = 0.11). The study concluded that mathematical calculations can complement the limitations imposed by equipment collisions, providing valuable insights for treatment planning.

Studi Rekonfigurasi Jaringan Distribusi 20 kV pada Penyulang DPRD ULP Cianjur Kota Menggunakan ETAP

In the distribution of electricity from electric power sources to consumers who are located far apart, they always experience losses, namely in the form of voltage drops and power losses. However, the voltage loss that occurs in the process of distributing electrical energy is a waste of energy if it is not controlled optimally. Concerning the quality of service, the main factor which becomes the benchmark is the continuity of service and the quality of service voltage. The impact of these losses results in low levels of service quality to customers. Analysis of voltage drop and power loss is needed to determine the size of the voltage drop at the end of the DPRD feeder network. The calculation of voltage drops and power loss uses simulation results of ETAP method. The results of mathematical calculations and simulations are analyzed to determine the factors that cause the voltage quality at the end of the DPRD feeder network to be below the standard service voltage of 20 kV. The results of the analysis and simulation show that the factors that cause the voltage quality at the end of the DPRD feeder to be below the standard of service quality level are the transformer loading system, the type of conductor, and the distance of the substation to the far end of the feeder network. Then the problem was resolved by changing the type of conductor and reconfiguring it by shifting part of the load to the Lampegan feeder so that the voltage profile at the end of the DPRD Feeder was initially 17.527 kV after reconfiguration increased to 18.137 kV.

Determination of factors of maximum influence on the occurrence of fires in conditions of limited a priori information in the war zone in the east of Ukraine

The expediency of using the inverted Floyd–Warshall algorithm for a deeper study of factors of maximum influence on the occurrence and development of fires in the war zones of Donetsk and Lugansk oblasts is shown. It relates to the fact that fire is one of the important parameters of the monitoring system that affects the ecological situation in the region. However, in the absence of a priori information about fires and hostilities, the formation of a set of factors influencing the occurrence and development of fires in the region is a laborious process. The primary assessment of a priori information allows generalising and averaging the factors that influence the occurrence of fires in these regions. The inverted Floyd–Warshall algorithm is a simple algorithm to implement, although to eliminate errors in mathematical calculations and to form adjacency matrices, a program code was developed in the Python programming language. Using the built-in visualisation software tools, a weighted oriented graph of factors influencing fires was built; the weights of these factors, determined at the initial stage, are also indicated on the edges of the graph. An adjacency matrix has been compiled, which contains information about the presence or absence of links between graph vertices. The factors of maximum influence on the occurrence and development of fires in Donetsk and Lugansk oblasts are determined, considering the specifics of the area and the results of hostilities. The results of the algorithm confirmed that hostilities create a fire hazard situation in the region. Due to the lack of a complete set of data, it becomes almost impossible to obtain results of mathematical calculations that are more accurate, since open-source data cannot provide errorless data on hostilities. For the same reason, the study area is not divided into separate segments in order to obtain more accurate results of mathematical calculations for each segment. Despite this, the software implementation of the inverted Floyd–Warshall algorithm is a universal method for solving the problem of finding and selecting factors of maximum and minimum influence on the occurrence of fires in environmental monitoring issues.

Regression Quadratic Method untuk Menganalisis Hubungan Sudut Kemiringan terhadap Radiasi dan Energi Panel Surya

The potential of rooftop solar power plants at Semarang State Polytechnic Mechanical Engineering Workshop has been researched. This study discusses one of the factors that affect the radiation received and energy sent to the grid, namely the angle of inclination in the solar panels The average radiation data received by solar panels with variations in tilt angle between 0 to 30° and azimuth angles at 0° facing north and 180° facing south are simulated using Helioscope software. Based on the results of mathematical calculations, it is estimated that the relationship between the tilt angle of the solar panel and the radiation received and the energy sent to the grid will form a quadratic curve. From the results of data processing with the Regression Quadratic Method, it was obtained that the data match was 99.6%. The results of calculations using the quadratic equation show that the angle of inclination of the solar panels for installation of a rooftop PLTS in Machine Workshop Polines is 11° with a radiation of 1775.6 kWh/m2 and a energy production of 13575.9kWh.

Pengaruh Penggunaan Media Gambar Terhadap Hasil Belajar IPS Siswa SDN 81 Palembang

This study aims to determine whether there is an effect of the use of image media on the social studies learning outcomes of SDN 81 Palembang students. This research method uses quantitative methods, namely research that emphasises the amount of data collected. Basically the view of the role of value, then the quantitative approach sees everything as never value-free, objective and must be as it is. The results of quantitative research are presented in the form of mathematical calculation results. The data collection techniques used were observation, interviews, and documentation. Data analysis techniques use learning outcomes analysis and image media analysis. Based on the results of research and discussion of the Effect of the Use of Image Media on Social Studies Learning Outcomes of SDN 81 Palembang Students. The increase occurred in the pretest and posttest with evidence of an increase in: 1). The use of quantitative methods can, increase student success on the material types of economic activities. 2). Through the application of quantitative methods with props in accordance with the material can improve student learning outcomes, 3). The percentage of student learning completeness has increased significantly after the improvement of learning there are 27 students out of 35 students. In the improvement of learning on the evaluation of learning improvements there are 9 students on the improvement of pretest learning increased, students who scored 70 and above became 27 students or 65% of 35 students and on the improvement of the pretest to 81%.

Substantiating the rock mass control parameters based on the geomechanical model of the Severny Katpar deposit, Kazakhstan

Purpose. The research purpose is to develop a geomechanical model for ensuring the safety of mining operations by determining the optimal slope angles and probabilistic assessment of the stability of the open-pit walls. Methods. Three-dimensional geomechanical models for surface mining of deposits have been developed based on calculations of the stability factor (safety factor SF) of the open-pit walls in the Rocscience program to determine the rock mass stress-strain state at the end of mining using the finite element method. The geological wireframe model (GWM) has been built on the basis of the available geological sections, horizon plans and the results of the engineering-geological surveys using the Surpac geoinformation system. Findings. Strength reduction factor (SRF) has been determined taking into account the physical-mechanical properties of rocks that constitute the near-wall mass. An assessment of the stability of walls according to the selected geological sections is given, taking into account the projected contour of the Severny Katpar open-pit walls. The calculation of the projected contour stability of the open-pit walls by several different methods has revealed that the open-pit walls are generally stable. The open-pit parameters at the end of mining have been determined. Originality. For the first time, it has been determined that in the Southern and South-Western area of the Severny Katpar open-pit wall in the horizons +700…+400, there is a decrease in SF from 1.18 to 1.41 due to the predominant occurrence of siltstones and tectonic disturbances of the walls. Practical implications. The mathematical calculation results of the stability of the projected contour walls in the Severny Katpar open pit have been generalized. In addition, a geological and structural wire-frame model of the deposit has been developed, which makes it possible to ensure the safety of mining operations in the open pit.

Multi-objective T-S fuzzy control of Covid-19 spread model: An LMI approach

Due to the importance of control actions in spreading coronavirus disease, this paper is devoted to first modeling and then proposing an appropriate controller for this model. In the modeling procedure, we used a nonlinear mathematical model for the covid-19 outbreak to form a T-S fuzzy model. Then, for proposing the suitable controller, multiple optimization techniques including Linear Quadratic Regulator (LQR) and mixed H2-H∞ are taken into account. The mentioned controller is chosen because the model of corona-virus spread is not only full of disturbances like a sudden increase in infected people, but also noises such as unavailability of the exact number of each compartment. The controller is simulated accordingly to validate the results of mathematical calculations, and a comparative analysis is presented to investigate the different situations of the problem. Comparing the results of controlled and uncontrolled situations, it can be observed that we can tackle the devastating hazards of the covid-19 outbreak effectively if the suggested approaches and policies of controlling interventions are executed, appropriately.

Experimental Studies of Mechanical-Electrical Transformations during the Destructive Processes Developing in Dielectric Materials

A mechanical-electrical method for testing fractures developing within the stress-strain state changes of dielectric rock samples, as an example, is discussed here. The paper discusses the results of numerical and experimental studies of changes in the electromagnetic responses parameters under the pulse deterministic acoustic excitation of rock samples with different composition and texture. The paper presents the results of mathematical calculations of the stress concentration on cracks located along and across the sample axis, perpendicular to which deterministic acoustic pulses were introduced. The cracks presented in the sample volume are stress concentrators. With a different number and sizes of cracks perpendicular to the propagation of an acoustic pulse, the intensity of stresses and their type differ significantly. This circumstance indicates the influence of the structure of the samples and their dielectric properties on the parameters of electromagnetic signals when recording the results of mechanical and electrical transformations. Thus, the use of the method of mechanical-electrical transformations under compression can be used in testing the processes of the onset of crack formation and the development of fracture in solid-state dielectric materials and products.

Experimental Studies of Mechanical-Electrical Transformations during the Destructive Processes Developing in Dielectric Materials

A mechanical-electrical method for testing fractures developing within the stress-strain state changes of dielectric rock samples, as an example, is discussed here. The paper discusses the results of numerical and experimental studies of changes in the electromagnetic responses parameters under the pulse deterministic acoustic excitation of rock samples with different composition and texture. The paper presents the results of mathematical calculations of the stress concentration on cracks located along and across the sample axis, perpendicular to which deterministic acoustic pulses were introduced. The cracks presented in the sample volume are stress concentrators. With a different number and sizes of cracks perpendicular to the propagation of an acoustic pulse, the intensity of stresses and their type differ significantly. This circumstance indicates the influence of the structure of the samples and their dielectric properties on the parameters of electromagnetic signals when recording the results of mechanical and electrical transformations. Thus, the use of the method of mechanical-electrical transformations under compression can be used in testing the processes of the onset of crack formation and the development of fracture in solid-state dielectric materials and products.

Study on a new method of controlling casing shear deformation based on hollow glass microspheres cement sheath

Casing shear deformation caused by fault slip is a serious problem that restricts shale gas development. As yet, there is no effective method for controlling casing shear deformation. In this study, a cement sheath with hollow glass microspheres was used to prevent and mitigate casing deformation caused by a fault slip. An equivalent outer-diameter model was established. This model analyzes the mechanism by which casing shear deformation is controlled by a cement sheath with hollow glass microspheres under the condition of fault slip. The hollow glass microspheres in the cement sheath were broken owing to the strong shear forces of the fault slip. The internal volume of the hollow glass microspheres was released, which reduced the distance of the fault slip across the casing. The casing deformation was prevented or slowed down. A 3D assembly numerical model was established to evaluate the control effect of the hollow glass microspheres on casing shear deformation. Furthermore, the influences of slip distance, casing thickness, mechanical parameters of formation, mechanical parameters of the cement sheath, and crustal stress difference were analyzed. The mathematical calculation results showed that casing deformation increased with an increase in the fault slip distance, an increase in the stratum elastic modulus, and a decrease in the in situ stress difference. Therefore, the mass content of the hollow glass microspheres in the cement sheath also needs to be increased to ensure that the casing does not deform. The numerical analysis results showed that the change in casing thickness, Poisson’s ratio of formation, and mechanical parameters of the cement sheath had little effect on the mass content of hollow glass microspheres. Finally, the model was used to analyze the test wells in the Weirong Block, Sichuan, China. The calculation results showed that under the same condition of casing deformation of 8.23 mm in adjacent wells, casing shear deformation could be avoided by using a cement sheath with 11.9% hollow glass microspheres in the test well. This study provides a theoretical basis and reference for controlling the casing shear deformation caused by fault slip in shale gas wells.

Prototype Project SCADA on Hemodialysis Mixing Tank Operation

Pharmaceutical companies are an example of an industrial sector that uses technology-based systems in its production process. In this research the author will develop a SCADA (Supervisory Control Acquisition Data) system as a platform to solve several problems that are present in pharmaceutical production, namely in the drug production process using hemodilysis mixing tanks.
 The method that the author uses for this research is experimental research and data collection methods, which use the independent variables of the study, water level control and temperature control, while the independent variables related to the system reading results are displayed on the SCADA screen.
 Based on the results of mathematical calculations, it can be concluded that the production process using the SCADA system produces a more efficient time with a total time difference of 38 minutes/batch. Operations using SCADA technology within 24 hours were able to produce 4 batches of Infusion Bags, while using the conventional system only 3 batches. Operational needs using SCADA technology will generate more benefits in terms of cost and time, creating more effective and efficient work system for the company.

THE MODERN RESEARCHS ON GROUNDWATER RESOURCES OF MOIST SUBTROPICAL SOILS OF AZERBAIJAN

One of the leading areas of modern soil science is the study of groundwater for use in agriculture. The importance of this direction is determined by the development of methods for studying soil processes. In uncultivated soils formed under natural vegetation, the approach of the groundwater level to the surface leads to soil salinization and waterlogging. Long-term and systematic irrigation in the Lerik region creates a completely new water and soil process. The reserves of humus, carbon, nitrogen and the C:N ratio were determined in pseudo-podzolized clayey mountain-forest yellow earth soils (Aric, Staqnic Cleyic Acrisols - Loamic) common in the zone of humid subtropics in the Lerik region located in the southern part of Azerbaijan. In order to turn uncultivated soils into arable land, it is necessary to create a mathematical model of groundwater level fluctuations, to determine the functional relationship between the amount of nutrients and the final product. The application of the results of mathematical calculations ensures the involvement of lands in agriculture and obtaining high productivity from these lands. The results of analyzes of the river waters chosen as the object of study show that there were no serious mineralization processes in the rivers. The mineralization of river waters in the Lerik region varied within 0.439-0.678 g/l. The content of magnesium in water taken from the Lerik region ranges from 0.021-0.037 g/l. The content of sodium and potassium ions in the salinity of water ranges from 0.061-0.083 g/l. According to the results of analyzes, it can be seen that the mineral composition of the Lerik River is useful for drinking and suitable for agriculture, as irrigation water.

Application of Mathematical and Experimental Approach in Description of Sedimentation of Powder Fillers in Epoxy Resin.

In this paper, sedimentation inhibition attempts were examined using colloidal silica in a mathematical and experimental approach. Experimental results were validated by a two-step verification process. It was demonstrated that application of quantitative metallography and hardness measurements in three different regions of samples allows us to describe the sedimentation process using modified Stokes law. Moreover, proper application of Stokes law allows one to determine the optimal colloidal silica amount, considering characteristics of applied filler (alumina or graphite). The results of mathematical calculations have been confirmed experimentally—the experimental results show good agreement with the calculated data.

Электромагнитные методы контроля изменений напряженно-деформированного состояния диэлектрических материалов

Mechanical-electrical and acoustic-electrical complex methods of testing cracking while changing the stress-strain state in dielectrics are discussed on the example of rock samples. The paper discusses the results of numerical and experimental studies of changes in the electromagnetic responses parameters under the pulse deterministic acoustic excitation of rock samples with different composition and texture. Also the results of mathematical calculations of the stress concentration on cracks located along the sample axis are presented, perpendicular to which deterministic acoustic pulses were introduced. The experimental studies results of sample electromagnetic emission with containing calcite and magnetite under uniaxial compression to fracture are shown. Regularities in the electromagnetic signals amplitudes changes during acoustic sounding in the process of «stepwise» uniaxial loading by compression to destruction are given.

Acoustic-electrical testing of defects in the cement-sand and cement-glass model samples

A complex method of acoustic-electrical testing of defects in dielectric samples made from cement-sand and cement-glass mixtures is discussed. The paper reports the results of studies of changes in the parameters of electromagnetic responses and their spectra under pulsed deterministic acoustic excitation of model samples with defects in the form of solid-state inclusions. The results of mathematical calculations of the time variation in the stress-strain state induced in a defective dielectric model sample by deterministic acoustic pulse are presented. The relationship is shown between the parameters of the acoustic excitation and the electromagnetic response to the impact in a magnetic field. The study revealed that the specific electrical resistance of the cement-sand and cement-glass mixtures differs significantly. Excitation of electrical double layers by acoustic pulses causes an electromagnetic signal, parameters of which depend on the parameters of the acoustic impact and acoustic and electrical properties of the material. As a result, a reduced specific electrical resistance of the mixture increases its conductivity. The numerical calculation of the propagation of the deterministic acoustic pulse showed that its parameters change when it passes through a defect with acoustic impedance different from that of the mixture used.

The Analysis of Angin Puting Beliung Risk Rate by Utilization of Remote Sensing and Geographic Information Systems in Semarang

This study examines the risk rate of Angin Puting Beliung in Semarang of Central Java. The Angin Puting Beliung is a local designation for small-scale tornadoes that occur in Indonesia, originates from differences in pressure of a weather system, leads to strong winds. Between January 2014 and December 2018, the occurrence of Angin Puting Beliung in Semarang city of Central Java reached 91 times with a total financial loss of around IDR 852,500,000 (USD 60,000). High population densities and settlements without being followed by control of spatial use and land-use change make Semarang more at risk of being hit by a tornado. This study specifically aims to determine the level of physical, social, and economic vulnerability as well as to analyze the risk level of Angin Puting Beliung in Semarang city. The survey is used as the main method in this study. Samples were taken to represent the population namely land cover, slope, and land surface air temperature with data analysis using a weighted tiered quantitative method to answer the purpose of knowing the distribution of hazard and vulnerability areas and analysis of the results of mathematical calculations to determine the risk of Angin Puting Beliung. The results obtained show that Semarang city has a high hazard level of 28,502% which is mostly found in the southwest and northeast of Semarang. High levels of vulnerability are in the sub-districts of West Semarang, Mijen, Gunung Pati, and Tembalang. The risk level with a high class ranks the least, namely from other classes with a distribution in the sub-district of Tugu and Tembalang, accounted at 16.294%.

К вопросу о подаче керосина в поток острого орошения основной ректификационной колонны установок АВТ

. In this article the possibility of suppling the kerosene fraction into the live reflux line of the K-2 column of the atmospheric vacuum pipestill units is reviewed. According to the results of mathematical calculations in the Petro-SIM software, the fraction 140-240°С was determined as optimal for supplying into the top live reflux line of the K-2 column of the atmospheric vacuum pipestill unit. This action makes it possible to reduce the load on the condensing system of the K-2 column of the atmospheric vacuum pipestill units; the heat potential of the hotter kerosene flow also increases, both for heating oil and for generating low-pressure steam. The article describes the advantages of the method.

A new approach for gas-water flow simulation in multi-fractured horizontal wells of shale gas reservoirs

Shale gas reservoirs demonstrate low matrix porosity and permeability, and show obvious heterogeneity due to the existence of natural fractures. During the production process, fracturing fluid can easily invade the reservoir and result in a low fracturing flowback rate. The existing numerical methods are troublesome and have poor convergence. Therefore, it is necessary to develop a new approach to study the gas-water two-phase flow in shale gas reservoirs. In this paper, fractal theory is used to quantitatively characterize the heterogeneous fractures. A Mathematical model considering fractal induced-fracture distribution and gas-water two-phase flow in shale reservoirs is established. The meshless weighted least squares (MWLS) method is applied, for the first time, to the numerical simulation of gas-water two-phase flow in multi-fractured horizontal wells of shale gas reservoirs. Based on the moving least squares approximation, the variation principle is derived in detail. A numerical model of gas-water two-phase flow in the shale gas reservoir fracturing horizontal well based on the meshless method is obtained. The gas and water production of fractured horizontal shale gas wells are predicted by the model. The model simulation results are found to be in good consistent with the mathematical calculation results obtained through finite difference method. but the proposed new approach shows significant higher calculation efficiency. In addition, by applying this new approach, The influences of fracture distribution, initial water saturation, and reservoir reconstruction degree on the utilization range and production were also systematically compared and analyzed. The results showed that the smaller the fracture fractal index a in the reservoir reform area, the lower the pressure, the higher the daily gas production and the daily water production, indicating that the fracture network is densely distributed and the production effect is better. The larger the initial water saturation resulted in the greater flow resistance of the gas phase and the decrease of daily gas production. When the fracture spacing decreases in reservoir reconstruction, the daily gas production increases, but the increase range is gradually reduced and it has little effect on the daily water production.

Microwave Method for Measuring Electrical Properties of the Materials

The article is about the development of a new non-destructive microwave method for measuring the electrophysical properties of materials, based on the method of transmission and reflection of a plane monochromatic wave through layered materials. The method has been verified by the results of numerical and field experiments. A data processing technique is described for obtaining complex values of dielectric and magnetic permeability based on an original measurement scheme. Based on the results of mathematical calculations, the laboratory model was created using an ultra-wideband antenna and a parabolic mirror. The optimal distance of the antenna from the parabolic mirror for focusing the electromagnetic field has been determined based on the simulation. Testing was carried out in the frequency range 3–13 GHz on two samples of materials (plexiglass and textolite) with known electrophysical properties. The obtained results showed the reliability of the developed method and its applicability. The measurement error was less than 2%.