In the paper the method of automatic control of the two stage hybrid sorption-compression refrigeration system for different ambient conditions is presented. The main advantages of the system are its environmental friendly working fluids and waste or renewable low temperature heat source utilization. The control algorithm is designed for operation in four seasons’ conditions. During cold seasons the heat from the second stage condenser, as waste heat, may be used to increase the temperature of the heat pump source. The system is composed of dependent subsystems with individual controls, however it is controlled by the computer program as master control. The issues related to the optimization of operation of the refrigeration system, taking into account the maximum usage of available renewable or waste heat sources, are discussed in the paper.

Pressure pulsations in volumetric compressors systems have an important influence on the compression power and reliability. This problem occurs not only in huge compressor systems, as in the natural gas piping, in gas mines or national transport systems, but also in a small refrigeration compressors in domestic applications. Nowadays, it is necessary to develop pressure pulsation damping elements which will be effective for different mass flow rate values. One of the solutions are passive damping elements in the form of various types of nozzles. In addition to the decrease of pressure pulsations value, the result is also an increase in power consumption of the compression. Therefore, shape optimization is necessary. In the article the possibility of optimizing the shape of such elements using computational simulations is discussed.

The article presents some types of problems that can occur during solving the inverse kinematics and the steps to prevent them. These problems concern the numerical singularities which occur when Euler angles are used to describe the orientation of the mechanism links in space. This paper proposes to eliminate the mentioned numerical singularities by replacing Euler angles with quaternions. The discussed issues were shown on the example of a backhoe excavator equipment system.

The article presents the issue of heat flow through internal supports of double-walled cryogenic vessels. The influence of the thermal resistance at the contact plane between supports and vessel materials is discussed. A simulation of heat flow through the support multilayer made of plastic is presented. The simulation takes into account the influence of temperature and local contact pressure on the thermal resistance.

The paper deals with visualization of results for simulation of a deformation process of a sample with a mushy zone. The numerical model consists of three basic subsystems: the mechanical, thermal and density changes parts. These describe both solid and semisolid deformation states. Taking into consideration their specific distribution graphical visualization is very helpful for understanding the course of the process. Moreover, a three-dimensional presentation is applied in various fields, ranging from medical imaging systems to technological processes assistance to scientific visualizations and entertainment. The stereoscopic imaging technique is still being developed. It is based on the idea of showing each eye the same scene from a bit different perspective. As an effect the illusion of depth is created due to the way the two images are interpreted by the human brain. Stereoscopy is not a new concept, but in the past few years a significant increase in the interest in this method of visualization could be observed. It is caused by computer and audio-visual technology development. In the paper several techniques of creating stereoscopic images are presented together with their physical bases and devices providing such functionality. The use of projection equipment and possibilities of its application to visualization of semi-solid steel deformation is discussed. Apart from that a description of an implementation of OpenGL specification for stereoscopic presentation of computer simulation results is provided.

This paper presents an attempt of using new capabilities of CFD tools in field of fluid-structure interaction simulation, which is called “immersed solids”. This techniques treats solids as objects immersed into fluid domain which moves along with the fluid. This paper presents comparison of selected CFD results of traditional approach and “immersed solids” technique on example of direct acting relief valve.

The aim of this work is to calculate the effective area of a compressor recirculation valve. Analytical solution and numerical modeling for compressible flow through a valve will be presented. Critical parameters of flow will be determined. Numerical modeling will be performed using ANSYS FLUENT. The results of the numerical solution will be compared with the analytical solutions.

The elements subjected to high temperatures are exposed to phenomena such as the creep, where time-dependent properties of materials should be considered. Many devices of the steam boiler work in creep conditions, what limits the time of their work. The chosen thick-walled superheater header is exposed to a high temperature and pressure and therefore it should be designed according to the European Standards. In this article, the standard requirements for a component operating in creep conditions are presented, and the FEM analysis is performed. In the FEM analysis, the proposed creep equation is used based on the results obtained from experimental tests.

This paper presents Failure Mode and Effects Analysis (FMEA) on the hydraulic cylinder using matrix analysis and artificial neural network. Functions for each cylinder components were identified. Also relationships between pairs for interacting components and their potential failures where identified. Training and testing of an artificial neural network was conducted in MATLAB software environment.

The paper presents a method of data acquisition from a DAQ card using a direct memory access (DMA) and an asynchronous read of data buffer with the FIFO queue. The method can be used to acquire measurement data in Windows™ system when the required read frequency is higher than the system’s clock frequency. The method was used in practice to measure high-speed pressure and position changes in a two cylinder hydraulic system with two-state fast switching valves.

The paper presents results of laboratory tests of linear guides in the application to move heavy loads. The first phase of the work included construction of a test bench in the form of a steel frame running on profiled rails using HIWIN type blocks. Subsequently, investigations involving movement of the frame with various loads were performed. In each case a driving force of an operator was measured. Based on the obtained results, average values of the resistance to motion coefficients were estimated.

The paper presents a developed database for recording intermediate states of a workpiece. This solution can be used for automation of the calculation process, intermediate states and blank design generation for wide sets of parts. The calculation formulas, decision parameters and definition of intermediate states are also presented in this paper. The results from the developed SQL queries are attached. The presented idea and implemented database will reduce the time of design of a blank for rotary and axisymmetric parts in machining processes.

The condition of steel deformation in a semi-solid state should be as isothermal as possible due to the very high sensitivity of material rheology to even small variations of temperature. The basic reason for uneven temperature distribution (melting zone) inside the sample body on the Gleeble thermo mechanical simulator is the contact with cold/warm copper handles. The semi-solid conditions in central parts of the sample cause even greater temperature gradient due to latent transformation heat. Such non-uniform temperature distribution is the source of significant differences in the microstructure and, hence, in material rheological properties. In the paper example results of tomographic studies were presented for both experimental variants (with warm and cold handles).

The process of experimental verification of the MacPhersons-strut mechanism model is presented. The mentioned model is used to estimate wheel load components based on measured internal reaction forces. Chosen constructional solutions of sensors mounting are described along with sensors calibration methods. The kinematic characteristics of a model and real suspension mechanism (measured on a test stand) are compared.

This paper presents the influence of deposition conditions on texture and stress results of TiN coatings deposited by using the PVD magnetron process. Modification of parameters was related to the changes of temperature and substrate potential. The article presents the results of an analysis of texture and stress measurement obtained by X-ray methods and the results of microhardness measurement.

This paper presents methods for automatic generation of 3D models of hydraulic components. For the purposes of generating models the authors’ own software and PTC Creo Parametric CAD system was used.

The paper presents a CFD analysis of flow forces acting on a spool of directional control valve type WE10J. This is a four-port, three-position, solenoid directly operated valve with a nominal diameter of 10 mm and working pressure up to 35 MPa. The aim of the study was to investigate whether hydraulic forces acting on the spool during the flow of working fluid through the valve could be reduced by changing the geometry of that spool. ANSYS/Fluent software was used for the CFD analysis.

The paper presents finite element analysis of stresses and deformations of planetary roller screw components. The finite element model takes into account the frictional contact between helical surfaces. The results of numerical calculations for the contact problem were compared with the theoretical solution based on the Hertz theory. The obtained results can be used in the development of design procedures of planetary roller screw.

The paper presents an application of the Finite Element Method (FEM) in stress analysis and optimization of thread profiles in cooperation of the roller with the screw in the planetary roller screw mechanism. The problem of the roller and the screw threads cooperation as well as related geometrical parameters were described. The optimization problem was formulated with the aim of obtaining a better effort of threads and lower contact pressure depending on the geometry.

In this paper we describe an algorithm for solving the one-dimensional Stefan problem by involving metal shrinkage. In this algorithm we use the finite element method supplemented by the procedures allowing to define the position of moving interface and the change material size associated with shrinkage. We present also some examples illustrating the precision of the presented method.

The aim of the paper is to present the issue of using computer-aided methods as well as 3D printing technologies and not typical materials connected with it. Selected problems that can occur while applying computer-aided methods and their solutions have also been described.

Photonic structures and their application are one of the most intensively studied areas of modern optics. They are used in devices such as blue lasers, optical fibres or optical add-drop multiplexers. The paper describes the possibility of designing the photonic structure of the optical demultiplexer using the application written by the authors.

This paper presents CFD simulation of solid particle transport by jet pump. Simulation was conducted using Lagrangian-Eulerian CFD approach. There is presented simulation of transport of mixture of water and solid particles with various density by jet pump with annular motive nozzle. The CFD simulations allowed to obtain trajectory for individual particles as well as theirs maximal velocity.

In this paper, we present our research on modeling learning motivation of students by analyzing class evaluation questionnaires, carried out with students as respondents at the end of each term to improve the courses in future semesters. We firstly defined three elements influencing learning motivation: (1) interest, (2) usefulness in the future and (3) satisfaction. Original questionnaire enquiring about those three elements was designed and conducted in multiple classes across different school years. Next, we conducted an experiment to classify students’ motivation for learning using the provided answers. The results of the experiment showed that students’ learning motivation can be estimated using the three elements defined in this study.

In studies of new materials or products, it is necessary to carry out a series of tests to determine the physical properties of the product as a function of the manufacturing process parameters. The technological process of making successive samples for both experimental and research purposes is a mechanism which is time-consuming and which usually requires considerable financial outlays. At the same time, scientific literature offers a large number of experimental results carried out for a similar range of problems. The idea conceived in this study is to create a model that, based on the results of experiments collected from the scientific literature, will reduce the number of necessary physical tests by replacing them with an effective mechanism estimating some of the technological process parameters. Consequently , the concept of an algorithm has been presented to estimate the parameters of the manufacturing process of ADI (Austempered Ductile Iron). It can operate as a fundamental part of a larger expert system, supporting the design and configuration of production processes in various industries. This article describes the results of tests showing the efficiency of the proposed solution and outlines plans for further development of the system to increase its effectiveness and usefulness.

The assessment of road pavements in terms of their properties and surface features is both complex and difficult. The indicators which describe the surface quality are eg. a longitudinal and transverse profile, a coefficient of friction, the International Roughness Index (IRI) and surface cracks. The article presents a method of using the data describing a real longitudinal profile of pavements, which was obtained by way of a self-constructed device named Walking-Profiler. It also proposes a way of calculating it with the use of numerical modelling of a Planograph, and also (simultaneously) the collected data can be used to calculate the International Roughness Index.

The paper presents the usage of the concavity index for the effective recognition of the concave, open manufacturing features like open pockets, through slots and steps. The determination of this index using B-Rep representation is presented in detail. This is a fragment of an algorithm for the recognition of manufacturing features defined in the STEP-NC standard.

This paper presents a modular system for the support of experiments and research in text classification. Usually the research process requires two general kinds of abilities. Firstly, to laboriously analyse the provided data, perform experiments and from the experiment results create materials for preparing a scientific paper such as tables or graphs. The second kind of task includes, for example, providing a creative discussion of the results. To help researchers and allow them to focus more on creative tasks, we provide a system which helps performing the laborious part of research. The system prepares datasets for experiments, automatically performs the experiments and from the results calculates the scores of Precision, Recall, F-score, Accuracy, Specificity and phi-coefficient. It also creates tables in the LaTex format containing all the results and it draws graphs depicting and informatively comparing each group of results.

We present a solution to integrate the database of the Department of Rural Roads (DRR) in Thailand and to utilize the date on the environment of the parallel computing. We define and classify the usage of the data according to the level of the collaboration for different sources. For the user interface of the integration, we provide a web-based environment with the technique of the HTML5.

This paper presents the results of a computer simulation, performed to check how the number of smart designs of experiment units affects the quality of information to be obtained in experimental research conducted on the basis of the analyzed designs. In the simulation, a real research object was replaced by a special testing function whose values were compared to the values predicted by the neural networks trained with the use of data sets based on smart designs of experiments containing various numbers of units.

This paper presents an analysis of comparing the effects of the application of the smart and traditional designs of experiment. The smart designs of experiment generated according to two various methods were compared to the central composite designs for two and three inputs. To check how the use of selected designs will affect the results of the experiment a computer simulation was performed, where a real research object was replaced by two special testing functions whose values were compared to the values predicted by the neural networks trained with the use of data sets based on compared smart and traditional designs of the experiment.

The scheme control system of a laboratory stand for gearbox and coupling testing, capable of fulfilling many miscellaneous requirements has been described in the paper. The innovative solution, as well as the benefits of the application, based on the Program Logic Controller, connected with electrical motor drives and a computer measurement system, have been described and depicted. Special features of the suggested solution, such as flexibility and ability to develop or adjust for another application, have been characterized.

In this paper some selected problems dealing with an influence of different throttling conditions on the flow structure inside a cross flow fan working in a unit incorporating a heat exchanger as well as on aerodynamic performances of a cross flow fan and unit have been studied. Different experimental and numerical methods have been used to verify and confirm selected flow phenomena. The local pressure loss as an effect of a heat exchanger resistance has been estimated taking into consideration some experimental results confirmed by the Finite Volume Method computation.

The functionality of the authors’ computer program which enables to analyze dynamics of special cars with a high gravity center, in particular, a technical rescue vehicle of fire service is presented in this article. The correctness of the analysis has been confirmed experimentally. The program consists of two essential parts: the calculation module and the animation module designed for three-dimensional visualization. Properly prepared input data in the XML format is processed by the calculation module which can solve the equations of motion including an uneven road surface. The results of this module are processed by the animation module performing a smooth computer animation. For mathematical modeling of road unevenness and presenting three-dimensional animated objects authors used an unconventional combination of the developed program with the Blender graphical environment.