bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing functional features of V-belt transmissions
Authors: Krawiec P , Pajtášová M , Meler F , Warguła Ł
Published: April 2020

The development of belt transmissions with wedge belts and new materials used to produce belts inspire designers and people who deal with the exploitation of belt drives to carry research on the possibilities of increasing the load and durability of the belts. It is necessary to know the actual mechanical and rheological characteristics of the belts in the range of their durability features and to comply with the conditions of proper transmission work. It is possible to find in literature many information referring to classic, single rubber belts. In case of polyurethane heat-sealed belts obtaining such information is not easy. It has been a starting point to carry out experimental research in order to determine the material characteristics of belt PU 75 A (red colour). The article presents experimental research results on creeping, cyclical squeezing and stretching of the belt; also the subjection of a side-slip and transmission efficiency in the torque function for PU 75 A belt was determined. The research results will be used to create a transmission model in Abaqus Explicit programme.
Analysis of the size of shredded particles in a multi-disc grinder
Authors: Śmigielski G , Tyszczuk K , Mroziński A
Published: April 2020

The result of a shredding process should be a product of specific dimensions obtained with the consumption of the minimum amount of energy per unit of weight. There are several parameters that affect the efficiency and quality of the shredding process (including temperature and rotational speed). The article presents the station of a multi-disk grinder whose design is based on a computer with a control and measurement application developed in the LabVIEW environment, a CMOS camera, and a multi-functional DAQ device. The station makes it possible to look for optimum settings of the control system in order to obtain an appropriate particle size. The size of the shredded particles is justified by the requirements of the downstream process: extrusion in the case of plastics and digestibility in the case of biological materials.
Complex designing of granulation units with application of computer and software modeling: case “Vortex granulator”
Authors: Artyukhov A , Artyukhova N , Krmela J , Krmelová V
Published: April 2020

The article is devoted to the description of the complex method to design granulation unit, which is based on the joint use of the computer modeling results on the simulation models and software modeling based on author’s software products. The description of the software package Granulation Unit© to carrying out the structural and technological calculations for the granulation unit is given. The role of computer and software modeling in the general design algorithm of the granulation unit is shown. The optimization criteria are selected and an algorithm of design optimization for granulation unit is described using the example of the “Vortex Granulator” case. A general method of granulation unit designing “turnkey” with the use of automated design elements is presented. The results of automated calculations form the base to design an industrial granulation unit for the porous ammonium nitrate production. On the example of a specific product of the granulation unit (porous ammonium nitrate), the author’s software product is presented to determine the quality of the porous surface in the granule. This approach in modeling allows to create the automated systems for the optimization calculation of granulation equipment.
Analysis of angular deflection of bearing node in machine with toothed transport belt
Authors: Berdychowski M , Malujda I , Wałęsa K , Fierek A
Published: April 2020

The available CAE solutions are a significant assistance when carrying out engineering works. They facilitate conceptual design, design and carrying out strength calculations. These tools are very popular because of the simplicity of use and the ability to obtain quite accurate distributions of structural stress and strain. Unfortunately, when designing shafts the rotation angle values on supports are equally important. The present article draws attention to the essential problem of the misalignment of roller bearing assemblies caused, among others, by exceeded allowable angles of rotation. The article furthermore presents the results of the analysis which aimed to determine the influence of selected geometrical characteristics of the shaft as well as the bearing span on the value of the shaft angle of rotation at the supports.
Possibilities of modelling the bolts in program ANSYS
Authors: Bocko J , Lengvarský P , Huňady R
Published: April 2020

In this paper, the techniques of modelling bolts in program ANSYS are investigated. Several types of the bolt models are proposed and compared. The finite element models with solid bolt with and without thread, and no-solid model. The pretension effect is applied for all types of bolts. Different types of connections and finite elements are used for modelling. In addition, the assembled mechanical structure is loaded by pretension effect and the field of stress and displacement of points around holes for bolts are investigated. Moreover, the stresses in the bolts computed by three-dimensional finite elements are investigated.
Preliminary research of strength of glued connections of plastic elements
Authors: Fierek A , Malujda I , Wilczyński D , Wałęsa K
Published: April 2020

This paper presents the preliminary research of peel test of the adhesive bonding for materials using on parts of seating for public transport vehicles. Researches are focused on cooperation with the industry and their validity is conditioned by the need to automate the process of adhesive coat application. For the purpose of the experiment, two of the three materials composing the seat were selected: polyamide PA6 and polyurethane foam. Tensile strength tests were performed on polyurethane foam treated as the weakest component. At the further stage of the work, two adhesives were selected to for bond strength test. The first one was the adhesive used in the production of seats, the second one was selected on the basis of literature review. In both cases, adhesive was applied by spraying. Thus the bond strength was tested with the peel test as per EN 28510. The type of failure was also determined and the results are compared. Based on the obtained results, specific conclusions have been drawn to guide further research.
Analysis of shaft selection in terms of stiffness and mass
Authors: Fierek A , Malujda I , Wilczyński D , Wałęsa K
Published: April 2020

The currently available computer aided design tools significantly accelerate the design process. They enable creation of 3D structures and elements and allow checking their strength or other properties with the use of the different analytical and simulation modules. Selection of appropriate elements in terms of strength and cost is important for any engineering project. The above-mentioned tools for designing and performing analyses were used to select an appropriate shaft to drive the toothed belt. Analyses were needed to verify the designed shaft length and mounting method. The tested shaft was 1200 mm long, supported at one end. Shafts with different geometries, i.e. solid and hollow with different diameters were selected, taking into the consideration the design assumptions. The weight and rigidity of the system were considered relevant and were investigated. The paper presents the input parameters of the analysis and the simulation outputs. These are compared with the results of analytical calculations. The research outputs include the conclusion that while offering a higher rigidity, hollow shafts involve mounting design challenges.
Preliminary analysis of the sensitivity of the algebraic dry ice agglomeration model using multi-channel dies to change their geometrical parameters
Authors: Górecki J
Published: April 2020

The article presents the results of a preliminary analysis of the algebraic sensitivity of the model describing the change in the limit values of densification stress in the process of dry ice agglomeration using multi-channel dies in the piston technique. In the available literature, it was noted that the limit value of compaction stresses significantly exceeds the effective value. This justifies the sense of undertaking work on the development of a multi-channel die that allows the reduction of the value of the indicated stress, which will reduce the consumption of electricity necessary for the production of dry ice pellets. The sensitivity analysis performed is related to the attempt to determine the significance of the impact of individual geometric parameters of the multi-channel die on the value of the limit stress. The results will significantly contribute to the development of a work program related to the optimization of geometrical parameters of the tools used to implement the indicated process.
Construction design and structural analyse of transfer system
Authors: Jakubovičová L , Kopas P , Handrik M , Vaško M , Grega R , Šulka P
Published: April 2020

Modern transfer system device is used in industrial automatization and it ensures a smooth transfer of material along the tracks. The transfer system model was created in CAD system. Finite-element and modal analysis was created in Ansys Workbench software. The system consists of aluminium profiles from Bosh Rexroth firm, and it contains electric, pneumatic and control elements.
Design problems of axisymmetric connections in the aspect of machine engineering drawings
Authors: Kołodziej A , Dudziak M , Talaśka K
Published: April 2020

Axisymmetric connections are often employed in machine building. They can be used as static and movable connections. The final geometric form of elements comprising the axisymmetric connection is heavily dependent on the guidelines provided in the engineering drawing as well as the metrological process carried out as part of manufacturing. The denotation to maintain correct deviation within the framework of selected shape faults appears to be inaccurate. Companies manufacturing such components may control their measuring strategy to avoid a large number of rejected items. In the paper the influence of selected shape faults on coupling parameters within the axisymmetric connection as well as the effect of selected measurement strategy on the results of measurement of specific dimensions are presented. Furthermore, in the paper the guidelines for correct notation in the technical documentation to avoid ambiguity in interpretation have been defined.
Simulation of the impact bar top layer tensile test applying the Finite Elements Method
Authors: Marasová D , Ambriško Ľ , Caban Ľ , Semrád K
Published: April 2020

Impact bars represent the main structural components of impact idlers which are used to absorb the impact of the transported material at chutes in belt conveyance systems. An impact bar is a composite comprising three basic structural parts. The top part consists of a polyethylene or polyurethane layer; the middle part is flexible rubber absorbing the dynamic impacts of the falling material; and the lower part is formed from the steel carrying profile. Mathematical modelling of the belt conveyance elements is one of the methods of obtaining relevant results regarding their dynamic load when being impacted by the falling material. The tensile test simulation, performed applying the Finite Element Method, was performed using the Abaqus 6.14 software. On the basis of the true laboratory experimental test, the tension diagram was created and subsequently used as the input for the mathematical model. For the purpose of examination of the plastic behaviour in the Abaqus environment, the logarithmic strain was used and the plastic load zone was demarcated. The elastic zone of relative deformation was determined by the modulus of elasticity. The present article contains the graphical interpretation of the separation of reversible and permanent relative deformations, model geometry, defined material characteristics and boundary conditions, as well as analysis results. The outcome is a high degree of concordance of the results of the laboratory experimental test and the results of the FEM analysis in terms of relative elongation at the breaking point and stress at the breaking point of the tested specimen of the impact bar top layer. The max. difference in the plastic deformation doesn’t exceed 10 %.
Sensitivity study of spindle assembly used for thermal displacement reduction
Authors: Marek V , Hudec Z
Published: April 2020

The article is focused on the thermal behaviour of a spindle of a milling centre. This is a typical problem of high precision machines, which produce heat as a negative implication of production activity. Thermal loading influents productivity and precision of milling centre. Thermal transfer simulations, computed fluid dynamic solutions and finite element methods in general are vital sources of information about behaviour of machine parts influenced by heat loading. Reduction of thermal displacement is a crucial task. The sensitivity study, based on a complex case study, is able to identify features with significant influence on overall deformation. Complex case consists of detail subcase analysis. Identified parts require modifications to decrease of deformations. Results are compared with new productive computation method based on macro-models. Combination of these methods defines productive methodology which leads to fast prediction and accurate simulation.
Evaluate of time delays influence on effectiveness of nonlinear saturation controller. Part II: Numerical results
Authors: Mitura A , Rusinek R
Published: April 2020

In this paper selected results of numerical calculations are presented. For the beam model with delayed saturation controller the values of two indicators were determined. Firstly, the effect of time delays on the beam vibration level is determined. Next, numerical calculations describing an impact of delays on the kind of beam motion are performed. Quantitative and qualitative analysis of saturation controller effectiveness is also done.
Analysis and structuring diagnostic large volume data of technical condition of complex equipment in transport
Authors: Vychuzhanin V V , Rudnichenko N R , Sagova Z , Smieszek M , Cherniavskyi V V , Golovan A I , Volodarets M V
Published: April 2020

The paper presents the results of the classification analysis model for structuring of processed large volumes of heterogeneous diagnostic data about the technical state of complex equipment in transport development and research. Concept for the description and structuring of big data is proposed based on the formation of a metadata scheme using logical breakdown of all technical diagnostic data on the output variable - the technical condition of complex technical equipment in transport. A functional assessment of the technical condition complex technical system’s elements in transport is developed based on the application of methods for assessing structural and functional risks of failures. The article presents the results of assessing the accuracy of the input data sets classification using created decision trees models to effectively structuring and presenting the data in order to ensure that the procedures for their further analysis are performed. As a result of using the developed simulation model of structuring and presenting large heterogeneous diagnostic data volumes about the state of complex technical equipment in transport the time costs were reduced and the efficiency of analytical operations to study data for solving diagnostic problems and predicting complex system’s technical condition was improved.
Generating the cloud of points from the phase images
Authors: Stalmach O , Stalmachova K , Barnik F , Pobijak J
Published: April 2020

This article deals with the generating the cloud of points from the phase images. These phase images are similar to phase images which are generated during non-destructive testing using an infrared camera. In the first step the model of sample with the defects is created in the CAD software. Next the lock-in method is applied to the results from the numerical thermal FEM analysis and the phase images are created in the software MATLAB. Phase image representing the 2D image of the material at a certain depth under the surface of the model. From these phase images the coordinates of the cloud of points are generated in the MATLAB.
Simulation of rifled tubes drawing process
Authors: Šuťák D , Zajac J , Hatala M , Botko F , Čižmár P , Bittner A , Beták P
Published: April 2020

Presented paper is focused on knowledge in the field of tube drawing process. The introduction consists of summarizing the current state of the art. In the material and methods section, it is a characteristic of the usability of rifled tubes for heat exchangers, which serve to better heat exchange between the medium and the tube. The following section describes the implementation of the experiment. This section shows the principle of pipe drawing using a grooved mandrel and a die. The result section is showing resulting a simulation of strength analyzes and the recorded values during the pulling tests. In conclusion, the aim of this paper is briefly explained, as well as the need to take into account the leading part of the mandrel, which may result in incorrect geometry and cavitation. In conclusion, the issue is mentioned, which is beneficial for science and research in the field of cold drawing of tubes. It is also about knowledge with internally shaped surface in energetic equipment.
Analysis of threaded connections under impact load
Authors: Talaśka K , Wojtkowiak D
Published: April 2020

Threaded connections are widely employed in machine construction as fasteners, most often under static loads, but can also occasionally come under impulse or impact load. The latter type of load is particularly dangerous for this type of components. The paper presents MES analysis of a threaded connection under impulse load. The analysis takes into account thread geometry and axial force load. The material for the connection elements was modeled as elastic material. The work presents 2D models usable for determining the stress on components under static load together with 3D models utilized for determining the state of stress in components under dynamic loads (impact, impulse).
The application of the Finite Element Method analysis in the process of designing the punching die for belt perforation
Authors: Wojtkowiak D , Talaśka K , Fierek A
Published: April 2020

The Finite Element Method (FEM) analysis has improved the process of designing modern machines, especially when the effective construction solution has to be found. In the paper authors have presented the application of this type of analysis based on the example of the construction of the punching die for belt perforation. For these machines the cooperation of the piercing punch and the die is crucial. Because of this, the analysis of the flexural rigidity of the head block and the punch plate provides useful information, which can be used to maintain proper alignment between the punch and the die during the perforation process. It may have a positive effect on the tool wear and the punching performance. Additionally, by using the topology optimization the mass of the punching die can be greatly reduced while maintaining enough rigidity. This effect is desired in automated machines for belt perforation, in which the punching die has to move with high velocities in order to create a designed pattern on the perforated belt with satisfying efficiency. In the presented research authors focused on determining the influence of the constructional parameters of the punching die on the deflection of the head-punch block. The obtained results and the presented methodology of performing the FEM analysis of such machines will help to improve their design process and find the effective construction solution.
Development and design of new mechanical forging presses
Authors: Zahalka M , Raz K
Published: April 2020

This article deals with the design of a new crank forging press. Forging press has to respond to higher number of customer requirements. Most of them can be divided into two categories – technological requirements and economic requirements. Technological requirements include forging of new materials which are less formable and forging of larger parts. Economic requirements are focused on dimension stability and the minimizing of the additional machining. The design of new machine must respond adequately to all requirements. Some requirements are in conflict. Several design changes are presented in the article. These changes are analyzed and their benefits described. Main design changes are focused on workspace, bearings and cranks. Virtual simulation of behaviour during forging process was used for the evaluation.
Vehicle collision simulation based on non-classic tire traces
Authors: Śledziński M , Lewandowski A
Published: April 2020

In traffic conditions, vehicle collisions often result in tire traces on the road, vehicles and humans. Tire traces on the road can have diverse characteristics. A non-classic form of such traces is the subject of the present analysis. The selected non-typical trace form is characterized by a segmental course with diverse geometric features. The goal of this work is a full analysis of the trace generation mechanism using modern simulation tools. In the paper, the influence of selected vehicle parameters and road surface characteristics on the trace form have been analyzed. Research results indicate the usefulness of PC-Crash software for analyzing road accidents, also in regards to non-typical tire traces.
Research on the compaction process of loose materials with use of helix technology
Authors: Berdychowski M , Wilczyński D , Wałęsa K , Górecki J
Published: April 2020

In present times, there is an emphasis on facilitating energy generation from renewable sources. The energy generated in this manner is considered green with low environmental impact. One of the sources of renewable energy is biomass. The term biomass refers to all kinds of natural (organic) materials like sawdust, which can be processed to generate energy. In practice, the majority of the biomass is processed before it can be utilized. This process usually entails compaction to form pellet or briquette. It calls for utilizing briquetting machines with sufficient efficiency. The article presents the results of experimental research on the process of sawdust compaction in a screw briquetting machine. During compaction, the values of moment on the screw were recorded. These data will be used in the design of more efficient briquetting machines.
Information and analytical system to monitor operating processes and environmental performance of vehicle propulsion systems
Authors: Mateichyk V , Saga M , Smieszek M , Tsiuman M , Goridko N , Gritsuk I , Symonenko R
Published: April 2020

The article describes the peculiarities of using the information and analytical system to study the operating processes of vehicle propulsion systems and to assess their environmental performance, particularly fuel consumption and harmful emissions under operating conditions. The study provides the functional structure of the information and analytical system. It contains the subsystems that enable to obtain and analyze data about the operating process in the cylinder, the subsystem for obtaining data from the engine control system, the subsystem for obtaining data about the operating mode of the propulsion system, the subsystem of data analysis and forecasting the vehicle propulsion system indicators in different operating modes. The case of using the information and analytical system has been shown to study the influence of exhaust gas recirculation on fuel efficiency and environmental performance indicators of the vehicle propulsion system in separate modes and under operating conditions.
Measurement and comparison study of deformation using extensometer and 2D DIC technology
Authors: Bárnik F , Sága M , Vaško M , Handrik M , Kopas P , Štalmach O , Dorčiak F
Published: April 2020

The article deals with a short study of deformation measurement two different approaches. First is measurement by extensometer which is the contact technology and second is 2D DIC, which is the optical and contactless method of measurement. The paper starts with introduction to the 2D DIC measure method and continue with results of measurements of both methods. In the conclusion there is comparing results of two presented experimental methods.
Influence of imperfections on dynamic properties of oscillating rod
Authors: Dekys V , Novak P , Milosavljevic D , Nekoranec M , Stalmach O
Published: April 2020

The paper deals with the analysis of the influence of boundary conditions on the dynamic properties of a mechanical system. The steel bar is fixed in one place so that it is inserted under the hydraulic press. The pressure force in the press changes and models the imperfect fixation of the bar. The effect of bond imperfection is evaluated based on rod vibration analysis. This problem is solved computationally, by FEM and the results are compared with experimental measurement.
Identification of mechanical properties of KORDCARBON-CPREG-200-T-3K-EP1-42-A composite
Authors: Krystek J , Zajíček M , Kottner R
Published: April 2020

This work is focused on the identification of mechanical properties of a composite from tension, compression and bending tests according to ASTM standards. Selected stiffness and strength parameters were identified. The composite, which was made from KORDCARBON-CPREG-200-T-3K-EP1-42-A prepreg, consists of woven fabric (twill) with carbon fibres and epoxy resin. Some of the parameters were identified using the numerical simulation of the tests in the finite element system Abaqus and using optimization algorithms of Isight software. The whole process of the identification was managed by scripts written in Python software.
Numerical and experimental analysis of a laser welded joint made of dissimilar materials S355 and 304 steel
Authors: Saternus Z , Piekarska W , Sapieta M , Kopas P
Published: April 2020

One of the latest trends in modern welding industry is joining materials with different physical properties. Performing such welded joints results from the needs of the modern industry (like aviation or automotive). It is required that welded joints have appropriate strength, anti-corrosion and heat properties. The welded joints of this type are quite troublesome due to the large differences between the materials being joined. This work presents numerical and experimental research of laser butt welding of dissimilar materials. Experimental tests were made for laser welding of S355 steel with 304 austenitic steel (X5CrNi18-10). Macroscopic research is performed. On the basis of experimental research numerical investigations of the thermomechanical phenomena of the welding process are carried out using commercial software. Numerical analysis takes into account temperature dependent thermomechanical properties of welded materials. The temperature distribution in the welded joint is determined on the basis of results of calculations. The shape of melted zone and heat affected zone are numerically estimated. Stress distributions and displacement field in welded joint are numerically determined. Obtained results of the numerical analysis are compared to the experimental results.
Finite element simulation of tensile test of composite materials manufactured by 3D printing
Authors: Žmindák M , Novák P , Soukup J , Milosavljevic D , Kaco M
Published: April 2020

A principle of 3D printing is based on formation of continuous layers of materials up to a formation of the final shape. Materials for production of given components are composite materials, especially on the basis of so-termed CFRP, CRP, (carbon fibre – so-termed polymers reinforced by carbon fibres). The objective of this paper is to predict the deformation length of carbon/onyx composite laminates using Finite Element Analysis (FEA) and compare with universal testing machine INOVA FU 160 deformation results through the tensile load. Specimen were printed at raster orientation angles of 0°, 45° and 90° to test orientation effects on part strength. 16 ply CFRP specimens with various stacking sequences were analysed for their strength and displacements. A shell model has been established for simulation of the tensile test composite specimen which enables to understand the mechanical strength and strain at failure of the composite materials. The simulations of experiment are provided in FEM program ANSYS and ANSYS/Workbench.
The effect of temperature and storage time on mechanical properties of polyamides
Authors: Bakošová D
Published: April 2020

This work is deals with the influence of temperature and storage time on selected mechanical properties of polyamides. These properties were determined using an impact test Charpy hammer and static test strength. The tests were carried out on three types of polyamides PA 6 BT, PA 6 GF 20 and PA 6 CF 20. The samples were stored for 2, 5, 7, 14, 28, 56, 84 and 120 days with a storage temperature of -20 °C (the freezer), 21 °C (room temperature) and 70 °C (furnace, heated at a given temperature). At the indicated times, we performed the test set and evaluated the mechanical properties observed.
The heat treatment impact on microstucture quality of 14 260 bearing steel
Authors: Vavro J , Pešlová F
Published: April 2020

The paper deals with the investigation of the heat treatment impact on the microstructure quality of the bearing steel. The given heat treatment process as well as its impact on quality was determined for 14 260 material ( the designation of the given steel is based on Slovak Technical Standards). Unsuitable conditions of hardening process could be seen in the final steel microstructure as well as in values of mechanical properties. The structural heterogeneity and unsuitable processing conditions of the heat treatment led to pitting and premature initiation of the ruprure. The given condition can lead to the component lifetime reduction, and even to the various technical collisions. The mentioned investigation was performed for a component that is mechanically and thermally loaded in its service, where stress-strain states are not allowed. If the material is heterogeneous, even after the heat treatment, there is a risk of immediate destruction of the component and it was also evident in this case. Continuous inspection of the microstructure of the heat treated bearing steel can eliminate as well as prevent from undesirable conditions during the operation of the given structural component.
Evaluation of the protective PE foils properties after exposure in various environments
Authors: Gaňa D , Markovičová L , Liptáková T
Published: April 2020

The subject of the research is testing of the polyethylene foils (PE) degradation exposed in various environments. The foils serve to protect transporting flasks and containers for the possible periodic repeated application. The experimental foils were exposed in three various aggressive environments (Coca-Cola, chloride cleaner and detergent) with different pH values. The time of exposure was 3 and 6 months. To study the changes of the PE foils properties, the rheological and tensile strength measurements were performed, as well as the microscopy of the surface. By the rheological measurements the changes of viscoelastic properties were determined. The rheological parameters (e.g. modulus of elasticity and viscosity, complex viscosity) react to the structural changes in the PE foils. The strength properties are also affected by the experimental environment. In this case the strength parameters were different in longitudinal and transversal directions.
The study of mechanical properties of magnetorheological elastomers under compressive stress
Authors: Kukla M , Fierek A , Berdychowski M , Kończak M
Published: April 2020

The study of magnetorheological elastomers is one of the major areas of searching for construction materials with unique properties. These are smart composite materials which constantly find new areas of use because they combine the advantages of elastomers and ferromagnetic materials. This article presents the results of study of the mechanical properties of magnetorheological elastomers under compressive stress. As part of the study, a series of compression cycles was performed at different magnetic induction values, strain amplitude and input frequency. The influence of each parameter on the material characteristics was determined utilizing a rheological model of a viscoelastic material. The presented results were supplemented with methodology of measurement and sample preparation as well as information related to the construction of the testing station.
Experimental research of the mechanical properties of the round drive belts made of thermoplastic elastomer
Authors: Wałęsa K , Malujda I , Górecki J
Published: April 2020

A lot of the industrial machines use belt transmission for power transfer. These mechanisms often use the round belts several millimetres in diameter, which are made of the thermoplastic elastomers, usually polyurethane. The mandatory step in their production process is bonding of belt ends, which is often performed by the butt welding, using the hot plate. In general, this operation comprises two main mechanical interactions between belts and the automatic welding equipment. The first one is a compression, performed by shaped grippers during heating and joining step. Compression proceeds both along the axis of the belt and in the radial direction. The second of them is shearing, performed by cutting edges, during belt preparation and flash removing step. Shearing is present both in a plane which is tangential to the belt outer surface and also in a plane which is perpendicular to the axis of the belt. To correctly develop the model of the whole welding process, both the proportionality modulus and the shear modulus are required. The paper demonstrates the procedure of the experimental determination of these parameters, with some assumptions which are valid for the hot plate welding process. There were presented the results of the compression test in the axial and radial directions, and results of the shearing test. Finally, the values of proportionality and shear modulus as a function of test parameters are presented.
Numerical estimation of heat affected zone in spirally laser quenched shaft
Authors: Domański T , Saga M , Kubiak M , Saternus Z , Novak P
Published: April 2020

This study concerns numerical modelling and computer simulation of thermal phenomena in spiral laser heating of shaft made of S355 steel. 3D numerical analysis is developed for the prediction of heat affected zone in Abaqus/FEA software. Power distribution of spirally moving heat source is implemented into additional DFLUX subroutine, written in Fortran programming language. Changing with temperature thermophysical properties are assumed in the analysis. The model of heat source motion takes into account the size of heat affected zone. Results of numerical analysis include temperature field, predicted heat affected zone and cooling rates. These results are a start point for the analysis of thermomechanical phenomena with the consideration of phase transformations in solid state.
Model of electricity consumption in a manufacturing company – time series decomposition
Authors: Michalková M , Ďurčanský P
Published: April 2020

Electricity has become a commodity capable of being bought, sold or traded. An electricity market is a system enabling purchases, through bids to buy or offers to sell, which can be useful for companies to lower electricity costs by short term trades. This new approach demands new ways of collecting, analysing and predicting not only electricity price, but in first place electricity consumption. The aim of the paper is to model electricity consumption of a manufacturing company. The trend, seasonal and random component, respectively, are identified.
Energy optimal trajectories for electro-mechanical systems
Authors: Oršanský P , Ftorek B , Vittek J
Published: April 2020

Electro-mechanical systems (EMS) efficiency improvement can result not only in significant energy savings but also can have positive impact on our environment. Progressive applications of EMS control as e.g. dynamical system of multi-parts robots are described by system of non-linear mutually coupled differential equations considering gravity, acceleration, Coriolis and centrifugal couplings together with parameter changes as a function of load. Using Euler-Lagrange optimization we discuss some results in decreasing energy demands for given electro-mechanical systems exploiting electric drives, which are typical for industrial and transportation applications e.g. robotic arm control, train movement control etc.
Dielectric loss behavior and microwaves absorption properties of TiB2 ceramic
Authors: Song Zhuoran , Sun Mengxiao , Wu Lipeng , Wu Fan , Xie Aming
Published: April 2020

Searching for microwaves absorption (MA) with outstanding resistance to harsh condition shows great potential in various special applications. As a typical high-temperature and conducting ceramic, TiB2 can meet this requirement, but its high electrical conductivity will lead to high reflection of electromagnetic waves. In this paper, we find that TiB2 ceramic can exhibit excellent MA performance after doping by C/N elements. The chemical structures, dielectric properties and MA performance of ZrB2 ceramic are systematically measured and analyzed. The MA performance of TiB2 ceramic reaches −21 dB at 8.00 GHz under a thickness of 2 mm. The results indicate that the MA performance of ZrB2 can be ascribed to the multiple nonlinear dielectric resonance and polarization relaxation mechanism. This research significantly expands the application scope of TiB2 ceramic to MA area.
Motivational factors mediate the association of general self-efficacy and performance outcomes in acutely hospitalised older patients
Authors: Reichardt Lucienne A , Aarden Jesse J , van Seben Rosanne , van der Schaaf Marike , Engelbert Raoul H H , van der Esch Martin , Twisk Jos W R , Bosch Jos A , Buurman Bianca M ,   Hospital-ADL study group
Published: April 2020

Objectives

To study (i) the association of general self-efficacy (GSE) on the course of subjective (i.e. basic and instrumental activities of daily living (ADLs and IADLs) and objective physical performance outcomes (short physical performance battery (SPPB)) among older persons from discharge up to 3 months post-discharge and (ii) the extent to whether motivational factors such as depressive symptoms, apathy and fatigue mediate this association.

Methods

Prospective multi-centre cohort of acutely hospitalised patients aged ≥70 (Hospital-ADL study). Structural equation modelling was used to analyse the structural relationships.

Results

The analytic sample included 236 acutely hospitalised patients. GSE had a significant total effect on the course of subjective and objective performance outcomes (ADLs: β = −0.21, P < 0.001, IADLs: β = −0.24, P < 0.001 and SPPB: β = 0.17, P < 0.001). However, when motivational factors as mediator were included into the same model, motivational factors (IADLs: β = 0.51, P < 0.001; SPPB: β = 0.49, P < 0.001) but not GSE remained significantly associated with IADLs (β = −0.06, P = 0.16) and SPPB (β = 0.002, P = 0.97). Motivational factors partially mediated the relationship between GSE and ADLs (β = −0.09, P = 0.04). The percentage of mediation was 55, 74 and 99% for ADLs, IADLs and SPPB, respectively.

Conclusions

Motivational factors and GSE are both associated with subjective and objective performance outcomes. However, the relationship between GSE and subjective and objective performance outcomes was highly mediated by motivational factors. Taken together, this suggests that GSE is important to being physically active but not sufficient to becoming more physical active in acutely hospitalised older patients; motivation is important to improving both subjective and objective performance.
Relationship between sarcopenia and orthostatic hypotension
Authors: Soysal Pinar , Kocyigit Suleyman Emre , Dokuzlar Ozge , Ates Bulut Esra , Smith Lee , Isik Ahmet Turan
Published: April 2020

Background

The relationship between sarcopenia and orthostatic hypotension (OH) is unclear.

Objectives

The aim of the present study was to investigate associations between sarcopenia/sarcopenia severity and OH.

Design

A total of 511 patients attending a geriatric outpatient clinic were included. OH was defined as a decrease in systolic and/or diastolic blood pressure of ≥ 20 mmHg and/or ≥ 10 mmHg, respectively, when one transitions from the supine to an upright position. OH was measured by the Head-up Tilt Table test at 1, 3 and 5 min (OH1, OH3 and OH5, respectively). Sarcopenia and its severity were defined according to the revised European consensus on definition and diagnosis.

Results

The mean age of the sample was 75.40 ± 7.35 years, and 69.9% were female. The prevalence of probable sarcopenia, sarcopenia and severe sarcopenia was 42.2%, 6.06% and 11.1%, respectively. After adjustment for all covariates, systolic OH1, OH1 and systolic OH5 were statistically significantly different between severe sarcopenia and the robust group (odds ratio [OR]: 3.26, confidence interval [CI] 0.98–10.84; P = 0.05 for systolic OH1; OR 4.31, CI 1.31–14.15; P = 0.016 for OH1; OR 4.09, CI 1.01–16.55; P = 0.048 for systolic OH5). Only systolic OH1 was statistically different between the sarcopenia and severe sarcopenia groups (OR 2.64, CI 1.87–8.73; P = 0.012). OH1 and OH5 were statistically significant different between severe sarcopenia and probable sarcopenia groups (P < 0.05); there was no relationship between the robust group and probable sarcopenia (P > 0.05).

Conclusions

There is a close relationship between sarcopenia and severe sarcopenia and OH in older adults. Therefore, when a healthcare practitioner is evaluating an older patient with sarcopenia, OH should also be evaluated, and vice versa.
Contemporary Classification and Diagnostic Evaluation of Hypereosinophilia
Authors: Mattis Daiva M , Wang Sa A , Lu Chuanyi M
Published: April 2020

Objectives

To provide an in-depth review of the classification and diagnostic evaluation of hypereosinophilia (HE), with a focus on eosinophilic neoplasms.

Methods

A review of published literature was performed, and exemplary HE cases were identified.

Results

Causes of HE are diverse and can be grouped under three categories: primary (neoplastic), secondary (reactive), and idiopathic. Advances in cytogenetics and molecular diagnostics have led to elucidation of the genetic basis for many neoplastic hypereosinophilic disorders. One common molecular feature is formation of a fusion gene, resulting in the expression of an aberrantly activated tyrosine kinase (TK). The World Health Organization endorsed a biologically oriented classification scheme and created a new major disease category, namely, “myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA, PDGFRB or FGFR1, or with PCM1-JAK2.” Rearrangement of other TK genes and activating somatic mutation(s) in TK genes have also been reported in eosinophilic neoplasms. Diagnostic evaluation of HE involves a combination of clinical, histopathologic, and immunophenotypic analyses, as well as molecular genetic testing, including next-generation sequencing-based mutation panels. The management of primary HE is largely guided by the underlying molecular genetic abnormalities.

Conclusions

A good knowledge of recent advances in HE is necessary to ensure prompt and accurate diagnosis, as well as to help optimize patient care.
Bioaccessibility of Nickel and Cobalt Released from Occupationally Relevant Alloy and Metal Powders at Simulated Human Exposure Scenarios
Authors: Wang Xuying , Odnevall Wallinder Inger , Hedberg Yolanda
Published: April 2020

Nickel (Ni) and cobalt (Co) release from chromium-alloy powders (different stainless steels and a nickel-based Inconel alloy) compared with Ni and Co metal powders was investigated at simulated human exposure scenarios (ingestion, skin contact, and inhalation) between 2 and 168 h. All investigated powders consisted of particles sized within the respirable range. The powder particles and their surface reactivity were studied by means of nitrogen adsorption and electrochemical, spectroscopic (X-ray photoelectron spectroscopy and atomic absorption spectroscopy), light scattering, and microscopic techniques. The release of both Ni and Co was highest in the acidic and complexing fluids simulating the gastric environment and an inhalation scenario of small powders (artificial lysosomal fluid). Relatively high corrosion resistance and lower levels of released Ni and Co were observed in all fluids for all alloy powders compared with the corresponding pure metals. The extent of released metals was low for powders with a passive surface oxide. This study strongly emphasizes the importance of considering alloying effects in toxicological classification and/or regulation of Ni and Co in alloys and metals.
Phylogenetic implications of the anatomical study of the Amburaneae clade (Fabaceae: Faboideae)
Authors: Silvério Pena Bento João Pedro , Scremin-Dias Edna , Alves Flávio Macedo , Mansano Vidal De Freitas , Sartori Ângela Lúcia Bagnatori
Published: April 2020

Phylogenetic analyses of early-diverging Faboideae have indicated that genera previously positioned in distinct tribes are instead closely related, e.g. in the Amburaneae clade, and the relatively recent rearrangements of many genera into clades has hampered the identification of morphological synapomorphies for previously unrecognized clades. Our aims are to evaluate anatomical vegetative characters of leaflets attached to reproductive features in the Amburaneae clade, to identify new synapomorphies for the clade and subclades, to identify characters supporting intergeneric relationships and diagnostic characters for the genus and species and to provide information about the morphology and histochemistry of secretory structures. The study was based on the anatomy of the leaflet of 19 species of the Amburaneae clade. Papillae cells, the presence of vascular system units and hypodermis are shared features of Amburaneae. Anatomical characters of the leaflet can be diagnostic at the generic and specific levels in Amburaneae. Secretory structures found in the clade are secretory cavities, secretory channels, idioblasts, mucilaginous epidermal cells and glandular trichomes. The broader concept of Amburaneae is reinforced here by morphological and molecular data, with the identification of new synapomorphies. Our dataset supports the intergeneric relationships resolved by molecular data.