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The paper deals with an experiment involving a determination of concrete resistance to sulphate corrosion. The most important output is an evaluation of various measurement methods. The paper includes a comprehensive manual of a new graphical technique, which has been developed for evaluations of sulphate resistance of cementitious materials. The summary presents a comparison of the results of the graphical method with the results and statistical evaluation of other measuring methods. [ABSTRACT FROM AUTHOR]

In view of the active development of computer-aided computing technologies with software tools for a wide range of engineering tasks, it becomes urgent to choose reasonable and proven methods of calculation that take into account the specific nature of the structure, and comparisons of results. The article considers the features and results of the calculation of the sheet piled quay wall (anchored bulkhead with one level of land tie), obtained using two commonly used specialised programs (CAD Hydrotechnika and PLAXIS 2D) as well as graphically using the example of the refurbished wharf. The main parameters analysed were maximum bending moments and force in the anchor traction. The analysis of the results showed that there was a significant variation in the values of the main parameters, which indicated that more research was needed to identify the reasons for the discrepancy and, if necessary, to correct the calculation methods and algorithms and to verify them. [ABSTRACT FROM AUTHOR]

The differential equations for indeterminate plate bending cases are complex due to presence of stresses in two-directions, especially when second order analysis is to be considered. In this case, the boundary conditions are coupled with the unknown reaction forces. Traditionally, analytical solutions are presented (Timoshenko and Krieger, 1959) in graphical manner for application to field problems. In the present paper, a graphical solution strategy is presented to avoid the total analytical solution for transcendental differential equations. Analytical solutions are adoptable for simple boundary and loading conditions, while numerical solutions strategies are more suitable and feasible for complexly-coupled boundary conditions. In the procedure presented in the paper, simple numerical integration and numerical differentiation procedures are used, that can be implemented using a computer with very basic configuration also. The method is especially useful in teaching-learning processes. The accuracy of the results from the proposed numerical procedure is presented for plate bending problems. [ABSTRACT FROM AUTHOR]

Today belt transmissions are popular in different areas of mechanical engineering, due to the lowest cost at high reliability, which are provided by the simplicity of design and high indicators of its parts manufacturability. The belt transmission consists of the following parts: a belt, a drive pulley and a driven pulley (additional parts may also be used). Determination of values, directions and points of interaction forces application of these parts will allow evaluating the efficiency of belt transmission. The analysis of interaction by calculation-graphical method of determination all forces acting in the belt contour plane will simplify their finding. It is necessary to take into account peculiarities of elastic belt operation on rigid pulleys and the way of its preliminary (initial) tensioning. Using of this method will allow accurately estimate parameters of belt transmission operation and simplify its design with the necessary indicators. [ABSTRACT FROM AUTHOR]

Nitrate and fluoride contamination in groundwater is one of the major emerging problems of the Northern- Karnataka region of India. Fluoride pollutants in groundwater are responsible for dental and skeletal fluorosis whereas nitrate contamination is highly responsible for methemoglobinemia (blue baby disease), respiratory system, kidney, and thyroid in children as well as adults. The study has been carried out to identify the geochemical processes and mechanism responsible for releasing nitrate and fluoride pollutions in the region. Sampling has been done in both monsoon periods such as pre-monsoon and post-monsoon seasons. Fluoride concentration varies from 0.65 mg/L to 1.97 mg/L in pre-monsoon whereas the nitrate concentrations vary from 12 mg/L to 96 mg/L. The post-monsoon sample shows that the fluoride and nitrate vary from 0.76 to 1.53 mg/L and 16 mg/L to 77 mg/L respectively. The worst fluoride-affected villages are Jidga, Kamanalli, Padsawli, Sakkarga, and Nagelagaon. Several diseases such as dental and skeletal fluorosis have been identified in the region. Intertrappean beds and enhance the rate of weathering of fluoride bearing minerals may be responsible for fluoride contamination whereas excess use of fertilizer is generally responsible for nitrate contamination in the region. [ABSTRACT FROM AUTHOR]

The Root Locus method of control system design was developed in the 1940's. It is a set of rules that helps in sketching the path traced by the roots of the closed loop characteristic equation of the system, as a parameter such as a controller gain, k, is varied. The procedure provides approximate sketching guidelines. Designs on control systems using the method are therefore not exact. This paper aims at a non-graphical method for finding the exact system parameters to place a pair of complex conjugate poles on a specified damping ratio line. The overall procedure is based on the exact solution of complex equations on the PC using numerical methods. [ABSTRACT FROM AUTHOR]

The paper considers the issues of determining the distance from an object to an arbitrary plane. Point N is defined as an object from which the distance is determined, triangle ABC is considered as a plane. The position of the vertices of a triangle in space is determined by the Cartesian coordinates of the points of its vertices. Three methods for solving the problem were applied: the mathematical method, the graphical method, the method of modeling the results. The mathematical method made it possible to use the analytically composed general equation of the plane α(ΔАВС), setting the values of the coordinates of its three points A, B and C. The vector form of the equation of the plane was used. A transformation is performed to obtain the general equation of the plane in a Cartesian rectangular coordinate system, and then, a transformation is carried out to the normal equation of the plane. The segment NE to the plane α is found. In addition, the problem is solved by the graphical method of descriptive geometry. From the point N a straight-line l is passed to the plane α, the determinant of which is the triangle ABC, at an angle equal to 90°. Then, the value of the resulting distance NE was determined by graphical methods. The accuracy of the graphical solution method was verified by solving analytical equations. 3D modeling made it possible to solve the same problem. To increase the visibility, visualization tools of the computer-aided design system were used. [ABSTRACT FROM AUTHOR]

The normal distribution is widely used in fatigue calculations of the strength or life of construction components. However, it is not recommended to use for calculations for probability equal to or less than 5%, which was written in standard ASTM E-739-10. For this purpose, Weibull distribution is proposed by standard ISO-12107. Unfortunately, this distribution has many methods to estimate parameters. Four methods were presented. It is a graphical method, method of moments, weighted moments method and maximum likelihood method. The worst results have obtained through a graphical method. Other methods have similar results. The purpose of the paper is to present and compare methods for estimating Weibull distribution for 3 parameters for fatigue strength. An example of such estimated distributions is for fatigue life for 760 MPa stress amplitude for steel SUJ2 for torsion load. [ABSTRACT FROM AUTHOR]

The paper evaluated the mean daily discharges at Hnilec River sub basin, which is located in the Hornád basin in eastern Slovakia. The daily flows were characterized based the graphical method FDC (flow duration curves). This method has a long history of use in water engineering, hydropower, planning and water use. The flows at three river meter stations in the Hnilec River and the anthropogenic impact of a reservoir on the flows in the river basin in the observed period were investigated. [ABSTRACT FROM AUTHOR]

Linear programming is one of the basic concepts to further study in applied mathematics and optimization. If the constraints of the linear programming problem form a convex region, then the problem must have an optimal solution. Cube is convex and, in terms of geometry, cube is very special. Cube has some special properties that all edges are congruent and also the all sides are congruent. Other special properties of the cube are related to orthogonality and parallelism. This paper discus linear programming problems with cube constraints. This research is study literature research to describe linear programming problems with cube constraints on geometrical angle. Considering the peculiarities of a cube, this linear programming problem must have an optimal solution. The results show the following points: 1) A cube is a convex polyhedron; 2) The steps for solving linear programming with cube constraints are analogous to the steps for solving linear programming in two dimensions using the graphical method, finding all the vertices of the cube and calculating the value of the objective function at all of the vertices, and then determining the vertex point that produces the optimal value; 3) The problem can have a unique solution (vertex) or have infinitely many solutions (the points along the edges or on the side planes of the cube). [ABSTRACT FROM AUTHOR]

This paper discusses the propulsion of hybrid cars with an internal combustion engine and two electric machines that form the so-called power-split transmission. The object of study are variants of such transmissions, which provide two modes of operation – with simple separation and with double separation of power. The task is to study the range of change of the gear ratio from the internal combustion engine to the drive wheels depending on the parameters of the mechanical and electrical part. In the mechanical part two or three ordinary planetary sets are used and it is possible to see how their design parameters (the ratio of the number of teeth of the central gears) affect the range, and in the electrical part – the range of rotation speed of the electrical machines. The results are illustrated through a graphical method for the analysis of planetary mechanisms. [ABSTRACT FROM AUTHOR]

Settlement and consolidation of cohesive sediment in a thin container under still water conditions were investigated in the laboratory. It is assumed that the processes of settling and consolidation only depend on the density profile as a function of time. Changing in density profiles, as well as the depth of the water-solution interface, were investigated. Four different density (ρsw) sample solutions were prepared for the experiment. The experiments concern and include: initial density, density profile, water-sediment interface, and settling rate. The two processes considered here are sediment deposition followed by consolidation at the bottom. In the settling phase, advection is more dominant, while in the consolidation phase diffusion or dispersion plays a role in the process. The two processes can be distinguished by a graphical method to determine the condition under which the settling rate decreases drastically and the density remains approximately constant. The corresponding density is referred to as the gelling density which is about 1370 – 1380 g/L. Initial density has a role in the relationship between density and settling velocity, where the higher the initial density, the higher the sediment deposition rate. All densities collected during the experiment were not higher than the gelling density. Therefore, the process in this research is mainly settlement. The consolidation process might occur if the solution is left for a longer period of time. [ABSTRACT FROM AUTHOR]

Tunnel number 6 of the Jakarta-Bandung high-speed rail project is located in the province of West Java. The rock mass classification is used in the tunnel construction Basic Quality (BQ). This classification is relatively new in Indonesia. In addition, this classification does not provide an empirical approach to determining rock mass excavation methods. This study aims to provide information about rock mass quality and excavatability. In this study, surface mapping, analysis of drilling data, face mapping, and laboratory tests were carried out to determine the quality of rock mass as well as to assess the excavatability of tunnels. The results showed that the rock masses were slightly to highly weathered and had exceptionally poor to poor quality based on the Q system. The three assessment methods of rock mass excavation, namely the grade system from Nq, the graphical method, and the modified GSI chart, showed relatively similar results. In the design stage of tunnel construction, where rock core data are available, the Pettifer and Fookes method is likely the most practical rock mass excavation assessment method as it uses the least parameters. The modified GSI method is useful for rock mass excavation assessment particularly during the construction stage, where the rock excavation face mapping is permitted. [ABSTRACT FROM AUTHOR]

The article is devoted to a comparison of methods for determining the position of the center of pressure of a rocket and assessing its static stability when studying the basics of jet propulsion in aerospace education. A simplified method, an analytical calculation, a graphical method and various practical approaches that can be used in the educational process are considered. The use of the proposed methods is considered on the example of designing an experimental model rocket. Comparison and evaluation of the results of calculations are carried out. [ABSTRACT FROM AUTHOR]

It was not sufficient to merely establish the amount of wear on friction surfaces in brake mechanisms for a certain period of time. The principal objective is to determine the intensity of wear on the friction mating surfaces in general, as this will enable us to evaluate the reliability of the braking systems in passenger vehicles under operating conditions. The main purpose of the paper is to substantiate a methodology for assessing the wear intensity in frictional interfaces specifically for disc brakes that are installed in passenger vehicles. The primary objectives of the research work were identified. Conducted, accordingly, is the analysis to determine the extent to which various parameters for braking vehicles influence the wear on friction surfaces in disc brakes. Our substantiation is based on observed patterns of friction surfaces wear for disc brake mechanisms. A mathematical method was developed for estimating the intensity of wear on friction surfaces in disc brake mechanisms. Devised, additionally, was a technique for experimental research involving cyclic emergency braking of a vehicle on a dry horizontal asphalt concrete road. An analytical-graphical method was adopted to simulate the wear process on the friction surfaces of disc brakes for such passenger vehicles as: Daewoo Lanos, Lada Priora, Chevrolet Aveo and Forza. Each braking cycle consists of 30 emergency braking sequences, with initial braking speeds ranging from 10 to 35 m / s. The vehicle used was fully loaded and the aerodynamic force of air resistance was taken into account. The wear intensity of the friction interface during the braking cycle was evaluated by a special criterion. This criterion was calculated as the average sum of the friction interface wear ratios (as the difference between the disc and the friction lining wear) and the corresponding braking distance at which the wear occurred. For clarity, all measurement results were presented in both graphical and tabular formats. Formulated, in conclusion, are the key findings along with the identified pursuits for future research. [ABSTRACT FROM AUTHOR]

A copula-based analysis is usually performed in hydrology for the purpose of water management and flood prevention by analyzing the hydrological attributes, such as rainfall volume and duration. The primary goal of this study is to fit the rainfall volume and duration into copulas. The analysis was conducted on six selected rainfall stations in Malaysia with hourly rainfall data. The correlation between volume and duration is measured by Kendalls correlation coefficient. Clayton, Gumbel-Hougard (GH), Frank and Joe copulas of Archimedean family are used and the parameter of the copulas is estimated using Maximum Likelihood Estimation (MLE). Akaikes Information Criterion (AIC), three graphical methods, and Goodness-of-Fit (GOF) tests are used to find the best parameter estimation of copulas. The three graphical methods used are the conditional distribution function of Y|X, the distribution function of the copula, and a nonparametric estimate of the distribution of the copula approach. The GOF tests are The Kolmogorov-Smirnov (K-S) and Chi-Square (χ2) tests. Results estimate that Frank copula is found to be suitable to represent the rainfall volume and duration for all stations. [ABSTRACT FROM AUTHOR]

Semi-Standard Young Tableaux includes many applications in combinatorics, group representations, invariant theory, symmetric functions, and the theory of algorithms. Out of the many combinatorial objects Semi-Standard Young Tableau (SSYT) is the one on k-symbols. This paper aims to present how to find hook lengths, formulae for evaluation of total number of standard and semi standard young tableaux.The Semi-Standard Young Tableaux are used to label the basis vectors of the standard or Young Yamanouchi basis of the symmetric group sn. This papergives a new graphical method to find ranking and unranking of the semi-standard Young tableau for a partition of degree n in sn. Graphical method of approach is explained forthe symmetric group s6 using a partition of degree 6 as an example. [ABSTRACT FROM AUTHOR]

Thin films of a wide-gap dielectric MgAl2O4 on quartz and Al2O3 substrates were obtained by magnetron sputtering. Formation of a buffer layer, presumably characterized by the cordierite phase, occurs when thin films are applied to quartz substrates. The thickness of the deposited layer was determined by method of envelope curves (d = 1.28±0.1 µm), as well as using the graphical method (d = 1.29±0.05 µm). [ABSTRACT FROM AUTHOR]

SQL injection attacks continue to be a significant danger to data-driven online applications. Hackers are increasingly gaining uncontrolled access to the back-end databases of online applications to steal, alter, and delete private data. As a result, safeguards must be implemented to combat the rising danger of SQL injection. This paper proposes using a model to detect these threats by applying the random forest algorithm as a primary mechanism for injection detection and using principal components analysis to reduce the dimensions of the data. Experiments show that after applying the principal components analysis model, it produces a data set with essential features in improving the model's accuracy, while random forests are a graphical method that is likely to exploit the tree-structure property inherent in SQL queries. Furthermore, after applying the proposed model, the results showed a good performance from where false positive and negative rate is in addition to the time complexity, even with the difference in the number of features in the set of data used. [ABSTRACT FROM AUTHOR]

Recently the interpolation bases of the hierarchical type have been used for the problem solving of the approximation of multiple arguments functions (such as in the finite-element method). In this work the cognitive graphical method of constructing of the hierarchical form bases on the serendipity finite elements is suggested, which allowed to get the alternative bases on a biquadratic finite element from the serendipity family without internal knots' inclusion. The cognitive-graphic method allowed to improve the known interpolation procedure of Taylor and to get the modified elements with irregular arrangement of knots. The proposed procedures are universal and are spread in the area of finite-elements. [ABSTRACT FROM AUTHOR]

Surface tension is an important physical property of biodiesel. It is directly affected by both temperature and pressure. Gibbs free energy additivity is used as an alternative approach to quantitative structure-property relationship (QSPR) in estimating surface tension at high temperature and pressure which correlate surface tension of biodiesels to their carbon numbers, number of double bonds of fatty acid are proposed. The estimation results of surface tension of biodiesel as well as canola, jatropha and soapnut biodiesel fuels at various temperatures and pressures up to 473 K and 7 MPa which the most accurate predictive model. The surface tension of biodiesel fuels showed a linear relationship with Gibbs energy additivity approach. The model was proposed to estimate surface tension at high pressure and developed using the measured data from the tests for each liquid fuel. [ABSTRACT FROM AUTHOR]

This research paper discusses methods of the descriptive geometry and 3D-modelling to determine the intersection lines of the subspaces and surfaces found in modern architectural and construction solutions in the design of buildings and structures. Moreover, the question of finding the distance from some given point to the subspace was considered, and it is necessary to perform a project for a future structure. The course of solving the problem of constructing the intersection line of two truncated conical surfaces with intersecting axes of symmetry of the surfaces is analyzed. To correctly perform this task, it is necessary to know the process of completing the task, while it is also necessary to have perseverance and accuracy, since incorrect constructions will lead to distortion of the result obtained. It is given the comparative assessment of these two methods for the complex and efficient implementation. [ABSTRACT FROM AUTHOR]

In the presented paper, the authors discuss the formation of professional skills of a future Physics teacher, the characteristics of the system of professional competencies and key competences in the third millennium based on the required competencies that teachers will have to pass on to their pupils defined in ISCED standards and the shift in the understanding of key competences of the Physics teacher in the rest of the period. The specific area on which the authors focus in the paper is the technical communication of the teacher of Physics and the means for its realization. [ABSTRACT FROM AUTHOR]