bluuebunny/crossref_metadata_2025 huggingface dataset:
Acceptable surface temperature of floor radiant heating system based on thermal comfort study in southern China
Authors: Lu Xingyu , Liu Hong , Wu Yuxin
Published: January 2019

In winter, people's demand for heating is stronger and stronger in southern China, and the floor radiant heating system is more and more popular. However, there are no suitable guidelines or standards for the floor temperature of the heating system in this area. The insulation performance of buildings in southern is not as good as other area which have central heating system. So the acceptable floor temperature suitable for this area needed to be studied.12 healthy college students participated as samples in this experiment. The floor surface temperature was controlled by varying the temperature of water flowing underneath the floor. The main conclusions were as follows: 1) the floor surface temperature directly affected the skin temperature of the foot and the thermal comfort of the foot. There was a significant statistical relationship between the floor surface temperature and the overall thermal sensation. 2) The acceptable floor temperature ranged from 26.1 °C to 34.3 °C for sitting positions and 24.6 °C ~34.7 °C for standing positions. 3) Considering the head thermal comfort and the health effects of the cumulative effect of long-term heat exposure, the recommended upper limit of the floor temperature in this experiment is 31°C.
Morphological, optical and electrical properties of spray coated zinc ethyl xanthates for decomposition within a poly(3-hexylthiophene-2,5-diyl) matrix
Authors: Bishop Matthew , Akinwolemiwa Bamidele , Zhang Lun , Peng Chuang , Hu Di
Published: January 2019

This work investigates the deposition of hybrid layers, for next generation in energy conversion, via spray coating. Understanding the effect that this deposition procedure has on these layers could lead to the rapid development of these technologies, for both laboratory applications and commercialisation. Synthesised zinc ethyl xanthate and poly(3-hexylthiophene-2,5-diyl) was spray-coated on substrates and heated to a temperature of 160 °C, to the hybrid film. Optical, morphological and conductive properties of these films were investigated and linked to the spray coating duration. It was revealed that shorter-duration spray times led to relatively low conductivity and smoother films, moreover, an increase in spraying duration also led to an increase in conductivity, but with increased roughness, from 6.178 nm to 8.317 nm. As the spray time was further increased factors, including film layering effects, led to a gradual decrease in conductivity accompanied by a decrease in the roughness. Smoother films were shown to result in higher light absorption, characterised by wider band gaps, which could be due to the crystal structure of the inorganic phase. The controllability of this rapid, facile, and inexpensive spray deposition process was then demonstrated in fabrication of prototype photovoltaic devices.
The Raman LIDAR for the pre-production phase of Cherenkov Telescope Array
Authors: Iarlori Marco , Pietropaolo Ermanno , Rizi Vincenzo , Aramo Carla , Valore Laura ,   for CTA Consortium, Silvestri Valerio , Cirella Alberto , Dughera Giovanni , Galli Stefano , Marengo Marco
Published: January 2019

The ARCADE Raman lidar has been tested and validated at L'Aquila before the deployment at CTA (Cherenkov Telescope Array) North site. Some modifications have been done on the original ARCADE system to improve its performances, and an extensive programme of measurements has been performed. The Raman lidar (RL) technique is discussed with specific care to the technical constrains of RL systems, and the signal analysis, i.e., the estimation of aerosol optical depth, volume backscatter coefficient, and water vapour profiles and their significance (errors and resolution). Some final comments and conclusions are outlined.
FRAM telescopes and their measurements of aerosol content at the Pierre Auger Observatory and at future sites of the Cherenkov Telescope Array
Authors: Janeček Petr , Ebr Jan , Juryšek Jakub , Prouza Michael , Blažek Jiří , Trávníček Petr , Mandát Dušan , Pech Miroslav , Karpov Sergey , Cunniffe Ronan , Mašek Martin , Jelínek Martin , Ebrová Ivana
Published: January 2019

A FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a system of a robotic mount, a large-format CCD camera and a fast telephoto lens that can be used for atmospheric monitoring at any site when information about the atmospheric transparency is required with high spatial or temporal resolution and where continuous use of laser-based methods for this purpose would interfere with other observations. The original FRAM has been operated at the Pierre Auger Observatory in Argentina for more than a decade, while three more FRAMs are foreseen to be used by the Cherenkov Telescope Array (CTA). The CTA FRAMs are being deployed ahead of time to characterize the properties of the sites prior to the operation of the CTA telescopes; one FRAM has been running on the planned future CTA site in Chile for a year while two others are expected to become operational before the end of 2018. We report on the hardware and current status of operation and/or deployment of all the FRAM instruments in question as well as on some of the preliminary results of integral aerosol measurements by the FRAMs in Argentina and Chile.
Development of a High Spectral Resolution Lidar for day-time measurements of aerosol extinction
Authors: Sannino Alessia , Boselli Antonella , Maisto Domenico , Porzio Alberto , Song Changbo , Spinelli Nicola , Wang Xuan
Published: January 2019

Lidar technique is the most performing way to obtain the atmospheric vertical profile of aerosol optical properties with high space-time resolution. With elastic scattering lidars, the retrieval of aerosol optical properties (as the extinction profile) is realizable only with assumptions on aerosol extinction-to-backscatter ratio or with Raman measurement achievable in night-time. In order to overcome these problems, the High Spectral Resolution Lidar (HSRL) technique has been examined. In this paper we present an innovative prototype of High Spectral Resolution Lidar realized at Physics Department of University “Federico II” of Naples for the LISA (LIdar for Space study of the Atmosphere) project in the framework of the China-Italy international cooperation between CNISM and BRIT. The prototype which represents a first step of a spaceborne HSRL, is based on a laser source at 1064nm and 532nm with high spectral resolution ability at 532nm. The separation between the molecular and the aerosol components was obtained through the use of a confocal Fabry-Perot interferometer (CFPI) cavity.
Atmospheric monitoring using the Cherenkov Transparency Coefficient for the Cherenkov Telescope Array
Authors: Stefanik Stanislav , Nosek Dalibor
Published: January 2019

The future ground-based gamma-ray observatory, the Cherenkov Telescope Array (CTA) will require reliable monitoring of the atmosphere which is an inherent part of the detector. We discuss here the implementation of the extended method of the Cherenkov Transparency Coeffcient for the atmospheric calibration for the CTA. The method estimates the atmospheric transmission of Cherenkov light, relying on the measurement of the rates of cosmic ray-induced air showers that trigger different pairs of telescopes. We examine the performance of our approach utilizing Monte Carlo simulations assuming various atmospheric conditions and CTA observation configurations.
Monitoring of the atmospheric electric field and cosmic-ray flux for the interpretation of results in high-energy astroparticle physics experiments
Authors: Chilingarian Ashot , Knapp Johannes , Zazyan Mary
Published: January 2019

Atmospheric electric fields influence experiments using the atmosphere as a detector for very weak fluxes of highest-energy gamma rays and protons/nuclei coming from galactic and extragalactic sources. Multiplication of electrons and gamma rays in strong atmospheric electric fields change particle numbers and energy spectra of the secondary shower particles and consequently influence the reconstructed properties of the primary particles. Here, we present a MC study using the CORSIKA package to explore and quantify these effects.
A determination of fundamental constants using HD+ ion and atomic hydrogen spectroscopy data
Authors: Constantin Florin Lucian
Published: January 2019

A determination of fundamental constants using HD+ ion spectroscopy data is discussed from comparisons between precision measurements and accurate theoretical predictions by taking into account recent measurements and updated CODATA values of the fundamental constants. The deuteron-proton mass ratio is determined with an uncertainty of 10-9. The ratio between the HD+ reduced mass and the electron mass is determined with an uncertainty of 7.3 × 10-10. The Rydberg constant, the proton-electron mass ratio and the deuteron-electron mass ratio are consistently determined with 10-9 , 10-6 , and 10-6 level uncertainties from an adjustment of the (v,L)=(0,0)→(0,1) and (v,L)=(0,2)→(8,3) HD+ ion transitions and of the (n,l,j,f)=1S1/2f=1→2S1/2f=1 atomic hydrogen transition. The result of the adjustment provides a test of the consistency of the two-body and three-body quantum electrodynamics energy level calculations for the atomic hydrogen and the HD+ ion.
Bloch-Messiah decomposition and Magnus expansion for parametric down-conversion with monochromatic pump: role of the gain
Authors: Lipfert Tobias , Horoshko Dmitri , Patera Giuseppe , Kolobov Mikhail
Published: January 2019

We consider the effect of different orders of Magnus expansion for the field transformation in type-I parametric down-conversion with a monochromatic pump. The exact solution, existing in this case, allows us to analyze the convergence of the Magnus expansion for the spectrum of squeezing and the angle of squeezing. We demonstrate how the convergence of the Magnus series depends on the parametric gain for various values of the phase mismatch. For each phase-mismatch angle we find the gain, which is the exact upper bound for the convergence of the Magnus series.
Decoherence assisted spin squeezing generation in superposition of tripartite GHZ and W states
Authors: Sharma Kapil K. , Ganguly Swaroop
Published: January 2019

In the present paper, we study spin squeezing under decoherence in the superposition of tripartite maximally entangled GHZ and W states. Here we use amplitude damping, phase damping and depolarisation channel. We have investigated the dynamics of spin squeezing with the interplay of super-position and decoherence parameters with different directions of the mean spin vector. We have found the mixture of GHZ and W states is robust against spin squeezing generation for amplitude damping and phase damping channels for certain directions of the mean spin vector. However, the depolarisation channel performs well for spin squeezing generation and generates permanent spin squeezing in the superposition of GHZ and W states.
On winning shifts of marked uniform substitutions
Authors: Peltomäki Jarkko , Salo Ville
Published: January 2019

The second author introduced with I. Törmä a two-player word-building game [Fund. Inform.132(2014) 131–152]. The game has a predetermined (possibly finite) choice sequence α1, α2, … of integers such that on roundnthe playerAchooses a subsetSnof size αnof some fixed finite alphabet and the playerBpicks a letter from the setSn. The outcome is determined by whether the word obtained by concatenating the lettersBpicked lies in a prescribed target setX(a win for playerA) or not (a win for playerB). Typically, we considerXto be a subshift. The winning shiftW(X) of a subshiftXis defined as the set of choice sequences for whichAhas a winning strategy when the target set is the language ofX. The winning shiftW(X) mirrors some properties ofX. For instance,W(X) andXhave the same entropy. Virtually nothing is known about the structure of the winning shifts of subshifts common in combinatorics on words. In this paper, we study the winning shifts of subshifts generated by marked uniform substitutions, and show that these winning shifts, viewed as subshifts, also have a substitutive structure. Particularly, we give an explicit description of the winning shift for the generalized Thue–Morse substitutions. It is known thatW(X) andXhave the same factor complexity. As an example application, we exploit this connection to give a simple derivation of the first difference and factor complexity functions of subshifts generated by marked substitutions. We describe these functions in particular detail for the generalized Thue–Morse substitutions.
On bonded sequential and parallel insertion systems
Authors: Holzer Markus , Truthe Bianca , Firdaus Yosman Ahmad
Published: January 2019

We introduce a new variant of insertion systems, namely bonded insertion systems. In such systems, words are not only formed by usual letters but also by bonds between letters. Words which can be inserted, have “free” bonds at their ends which control at which positions in a word they can be inserted (namely only there, where the bonds “fit”). Two kinds of bonded insertion systems are defined in this paper: so-called bonded sequential insertion systems and bonded parallel insertion systems. In a sequential system, there is only one word inserted at a time. In a parallel system, there is a word inserted at every possible position in parallel in one time step. We investigate the generative capacity of those two kinds and relate the families of generated languages to some families of the Chomsky hierarchy and to families of languages generated by Lindenmayer systems. Additionally, we investigate some closure properties.
Wear evaluation study of the multiple grooved pulleys with optical method
Authors: Krawiec Piotr , Warguła Łukasz , Waluś Konrad , Adamiec Jaroław
Published: January 2019

Multiple grooved pulley wear can be evaluated by using two methods, coordinate method and optical method. This paper presents the results of the research and the analysis of the geometrical features for this type of pulleys, which was obtained with the ATOS II optical system. In this method the evaluation of wear is made based on the comparison of the manufactured parts or assemblies with superimposing the CAD model and the surface model obtained from digitization. Existing differences can be easily determined by their visualization in the form of a colored map of deviations or profile differences. This method is subject to a methodological error, which is a result of the accuracy of the scan and the correctness of the model's fit. Optical techniques can be used to determine the accuracy of the geometric features for products made with any shaping technique (machining, plastic processing, incremental methods, etc.).
Digital possibilities of the reconstruction of machine parts
Authors: Paszta Piotr
Published: January 2019

A rapid and continuous development of the machinery and equipment manufacturing capabilities is currently going on. Using CAx programs, complex elements can be made in a straightforward and very fast manner. The creation and use of spatial scanners, photogrammetric methods and spatial modelling is intensively developing, too. A complete object can be produced without the help of tactile methods, using professional 3D scanners, scanners of one's own construction, a camera, or even a cell phone with an in-built camera. The article has described the capabilities of a 3D scanner, verified its accuracy, and has also discussed the capabilities of photogrammetric methods to reconstruct machine parts.
Measurement and analysis of parameters of the precise grinding system
Authors: Tyszczuk Krzysztof , Peszyński Kazimierz , Mroziński Adam , Śmigielski Grzegorz
Published: January 2019

The technological process of materials grinding, especially biological material with high oil content, is quite complex. There are several parameters that impact the performance and quality of the process (e.g. temperature, rotational speed). One of them is the air velocity at pneumatic conveying of grinding particles. The phenomena of pneumatic transport of seeds and its impact on product’s quality and grinding capacity is not methodologically recognized so far. The paper presents the construction details of measurement and control system and results of the research obtained during the laboratory tests. The results of the tests and their analysis will be used for design of a commercial precise grinder, which allowed to reach the optimum product’s capacity and quality, constituting the basis for biological diet supplements.
Creation of prototype 3D models using RAPID PROTOTYPING
Authors: Harušinec Jozef , Suchánek Andrej , Loulová Mária
Published: January 2019

The article deals with creating 3D models using RAPID PROTOTYPING technology. At present, we are witnessing the integration of new technologies into ordinary life. A good example is the use of FDM (fused deposition modeling) technology that primarily uses thermoplastics to create 3D models. A few years ago, the use of rapid prototyping technology was a prerogative of companies, research institutes and a narrow group of universities. Technologies such as FDM and STL (Stereolithography) have become affordable in the past few years for smaller businesses and individuals. The specific segment is the replicating rapid prototype RepRap (replicating rapid prototype), the extended version of which is the Prusa i3 printer.
Profiles synthesis through radii variation of arcs profile method
Authors: Lack Tomáš , Gerlici Juraj
Published: January 2019

The article deals with one of the ways of profile geometry design of a railway wheel and rail. The base for the creation of a new profile is an interactive attitude based on the modification of „the original shape which is defined by section of a railway wheel profile“, with to each other connected and exactly defined arcs radii. It is possible to change them according to shape needs of the final geometrical characteristics. Problems of the railway wheel/rail contact represents a basic point of any analysis which is connected with the moment of a railway vehicle on a track, with safety, speed, with comfort of people and goods transport. It is connected with the construction of new railway vehicles, with the reconstruction the old ones, with the approval (refusal) of vehicles into operation, with their evaluation as well as with the evaluation of track quality and their maintenance. It has a direct influence on the position of rail transport in the frame of the whole transport system, on economics, ecology and so on.
Numerical study of the relation between chosen statistical parameters of input stresses and cumulative fatigue damage provided rainflow decomposition
Authors: Sága Milan , Štalmach Ondrej , Blatnická Mária , Handrik Marian , Ságová Zuzana
Published: January 2019

The aim of the article is to present a series of numerical tests of the cumulative fatigue damage solution under assumption of random stress input. It is realised study of the influence of the statistical moments or power spectral density on the cumulative fatigue damage using well-known rainflow method. The distribution of the cumulative fatigue damage is determined for pre-defined material parameters.
Variability analysis of urban traffic noise measurands
Authors: Bąkowski Andrzej , Radziszewski Leszek , Świetlik Paweł , Dekýš Vladimir
Published: January 2019

The paper presents the analysis results of measurements recorded by road traffic and noise monitoring station. The station is located in a medium size town in Poland (Kielce) situated at the national road to Cracow. The traffic flow was measured over the period between January and December 2013 for twenty four hours a day. Statistical analysis methods were used to determine the variability and uncertainty of the results. The measurements from two vehicular lanes running towards the town and two lanes running towards Cracow were analyzed. The variability of the results was described using parameters such as the coefficient of variation and positional variation. The results of vehicle traffic measurements were used to simulate changes in the noise measurand variation within 1-hour intervals. The Nordic Prediction Method was used for this purpose. It was found that in most cases, the distribution of the tested variable was not normal. Box plots were used to assess whether outliers data occurred in the recorded results. The variability of noise and type A uncertainty was evaluated.
Investigation of the impact of geometry of the riser on the location and shape of shrinkage cavity
Authors: Skrzypczak Tomasz , Węgrzyn-Skrzypczak Ewa , Sowa Leszek
Published: January 2019

During solidification process the phenomenon of shrinkage cavity is often observed. It has negative impact on the structure and physical properties of the final product. To minimize the negative effect of shrinkage cavity the riser is commonly introduced to the solidifying system. If the riser is properly designed shrinkage cavity rather appears within its volume than in the other parts of the casting. It makes possible to obtain defect-free main part of the casting. Presented work shows the impact of the different shapes of the riser on the localization of the shrinkage cavity. The results are obtained with the use of an original computer program based on the finite element method (FEM). They are presented for three-dimensional case of solidification of three types of the riser. The comparison of the results is discussed in details.
The influence of the riser dimensions on the effectiveness of feeding solidifying cast elements
Authors: Sowa Leszek , Skrzypczak Tomasz , Kwiatoń Paweł
Published: January 2019

The mathematical model and numerical simulation results of metals alloy solidification process based on the finite element method (FEM) are presented in this paper. After completion of the mould filling process the main solidified of molten metal takes place and its shrinkage. The phenomenon of casting shrinkage cannot be avoided. However, it is possible to minimize the occurrence of its negative effects on the casting quality. The phenomenon of shrinkage defects formation was included in the numerical calculations and they were tried to reduce them. It is important aspect of this work which makes possible the prediction of the location of the casting defect depending on shape of the riser. The results of computer calculations of the solidification process of the three-dimensional casting together with the conical or cylindrical riser are discussed in detail and presented.
Analysis of a cross-flow influence for a turbulence progress in an initial segment of axisymmetric duct
Authors: Judt Wojciech , Bartoszewicz Jarosław
Published: January 2019

Influence for a nondisturbed stream by cross-flow is present in many technical applications. In part of applications, this phenomenon is caused intentionally, but in others, it is a side-effect. Flow through the closed duct is one of the most frequently realized types of flow in thermal devices. The paper shows an influence of cross-flow for a laminar stream, which is flowing through closed, round duct. The considered case was calculated in numerical calculations and analyzed during experimental research. Cross-flow stream was generated by four circular nozzles located on the duct walls in some distance from the duct inlet, which was distributed along the circumference of analyzed construction in the right angle to the mainstream. Experimental research was realized by a constant temperature anemometry measurement method. A numerical model of a fluid flow was created in ANSYS Fluent software. Unsteady numerical calculations of a cross-flow influence for a mainstream was realized with the Detached Delayed Eddy Dissipation model of turbulence application. Realized research established how a cross stream can turbulent a laminar flow in a closed, circular duct. Authors showed velocity distribution in the main duct after cross-flow influence and demonstrated, that this method allows ascending turbulence of a flow in external parts of fluid flow.
New model of lumbar spine biomechanics with the use of simulation analysis
Authors: Kubaszewski Łukasz , Dąbrowski Mikołaj , Talaśka Krzysztof , Wilczyński Dominik
Published: January 2019

The existing biomechanical models of the lumbo-sacral spine do not explain the role of the dorsal extensor muscle and fascia. The study attempts to explain the action of paraspinal muscles based on the mechanism of contraction and “hydro skeleton”. It was assumed that the muscle contracting produces hydrostatic pressure and in this way is able to resist and transfer loads. In this mechanism, inside ventricular pressure can modify the load transfer through the spine. To confirm the hypothesis discussed above, a simplified simulation model of the lumbar spine was built. For this purpose, scientific software named ABAQUS, using finite element methods was used. The model of the spine was mainly a kinematic model aimed at reflecting the impact of the spinal muscle function on lumbar lordosis.
Modeling of heat flow using commercial and authorial software on the example of a permanent magnet motor
Authors: Gawrońska Elżbieta , Dyja Robert , Będkowski Bartłomiej , Cyganik Łukasz
Published: January 2019

The aim of the work is the modeling of the heat flow in an electric motor with permanent magnets with a height of 56mm. Numerical calculations were carried out for a simplified 3D model prepared in the Autodesk Inventor solid modeling program. The bodies were prepared from the existing model and constructional documentation of the actual engine. In the next step, the simplified solid model was imported into a commercial Autodesk Simulation Multiphysics computing package and into authorial software in which it was supplied with appropriate material properties and discretized. In the next stage, the model was calibrated and verified by a preheating attempt of the actual object. The motor winding was supplied with direct current and was a heat source with a power of 40 W. Temperatures were recorded at selected points in the steady state. Then, on a discredited numerical model, computer simulations corresponding to the actual heating test were carried out. When comparing the temperature values obtained at the points corresponding to the measurement points, the model was calibrated, which corrected the thermal resistance parameters assumed in the calculation model. Finally, the model (after the implemented changes) was verified with results obtained with commercial and authorial software.
The temperature distribution during heating in hot plate welding process
Authors: Wałęsa Krzysztof , Malujda Ireneusz , Górecki Jan , Wilczyński Dominik
Published: January 2019

Most of the industrial machines use the belt transmission for the power transfer. These mechanisms often use the round belts with a few millimetres in diameter, which are made of the thermoplastic elastomers, especially the polyurethane. Their production process requires the bonding step, which is often performed by the butt welding, using the hot plate. To design the automatic welding machine in a proper way, the authors analyzed this process. One of the most important parameter which describes the hot plate welding is plasticized distance. Knowledge about its value is necessary to predict the length reduction of the belt during welding and will be used during the quality of the joint rating. To obtain value of this parameter the temperature distribution calculations are needed. The paper shows the results of the analytical calculations of the temperature distribution and their comparison with analyses performed by the FEM implements. Calculations were performed for the thermoplastic elastomer during the heating phase in the hot plate welding process.
Improvement of the bearing structure of the wagon-platform of the articulated type to ensure the reliability of the fixing on the deck of the railway ferry
Authors: Lovskaya Alyona , Gerlici Juraj , Fomin Oleksij , Kravchenko Kateryna , Prokopenko Pavlo , Lack Tomas
Published: January 2019

In the article the results of studies of loading of the bearing structure of a wagon-platform of an articulated type, created on the basis of the existing construction, during transportation on the railway ferry by sea are given. In order to ensure the reliability of the fixing of the bearing structure of the wagon-platform of the articulated type relative to the deck of the railway ferry, it is proposed to equip it with knots for fixing the chain ties. To study the dynamic loading of a wagon-platform of an articulated type during transportation on a railway ferry by sea, constructed a mathematical model of oscillations with angular displacements relative to the longitudinal axis of the vessel (loll/heel). The maximal values of accelerations, as components of dynamic load, acting on the bearing structure of a wagon-platform are determined. The obtained acceleration values are taken into account when calculating the strength of the bearing structure using the finite element method implemented in the CosmosWorks software environment. It is established that the maximum equivalent tension do not exceed permissible values. The carried out researches will promote increase of efficiency of combined transportations in the direction of the international transport corridors.
Analysis of the friction (spin) welding – preliminary study
Authors: Pietrzak Michał , Wałęsa Krzysztof , Górecki Jan , Berdychowski Maciej
Published: January 2019

This article applies to the glue-free bonding of the components made of thermoplastics, specific techniques that use friction heat to plasticize and then join two surfaces. The featured technique is a friction (spin) welding process. Welding parameters were investigated and presented. Spin welding is known to consist of four phases. Analytical calculations were made for the first step. They are focused on the changeability of welding parameters depending on weld velocity. In the next part of this article, calculations including the finite element method were performed. This provided additional data and visualization of the process, which were not available in analytical calculations. Final results of both methods were compared. This made it possible to verify the correctness of theoretical calculations and exactness of FEM analysis.
Experimental and numerical tests of the compaction process of loose material in the form of sawdust
Authors: Wilczyński Dominik , Berdychowski Maciej , Wojtkowiak Dominik , Górecki Jan , Wałęsa Krzysztof
Published: January 2019

The paper presents experimental investigations of the compaction process of loose material in the form of sawdust. These were compacted in the sleeve-punch assembly adapted for installation on a strength testing machine. Sawdust was compacted with a force suitable to obtain the desired compressive stress in the sample cross-section. The effect of the composition of the compacted sample was investigated by adding pine sawdust to 50% of the total sample's weight. The experimental compaction process was simulated by building its numerical model using the Drucker-Prager-Cap model. Obtained results of experimental tests carried out on a strength testing machine allowed to establish a numerical model of the sawdust compaction process in the Abaqus program and to assess the possibility of using the Drucker-Prager-Cap model for numerical simulation of compaction process of loose materials in the form of sawdust.
Evaluation of passenger riding comfort of a rail vehicle by means dynamic simulations
Authors: Suchánek Andrej , Loulová Mária , Harušinec Jozef
Published: January 2019

Dynamical analysis plays a key role in development and optimalization of rail vehicles. The article deals with simulation analysis of a rail vehicle with an active tilting system of the vehicle body, design of the rail vehicle in CAD program CATIA and dynamical analysis in program SIMPACK, with the RAIL expansion. Such body mounting on vehicle bogies is significantly more complicated than the design of conventional rail vehicles. The purpose of this type of body mounting is to increase the size of body tilt during ride in a curve and thus reduce the lateral unbalanced acceleration affecting the passengers, or allow higher driving speed in a curve with the same radius while keeping the lateral acceleration value respectively. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analyzed. We determined the average value of passenger comfort from the simulation results. We have determined the value of passenger comfort during the ride in a curve from the simulation results.
Assessment of variability of acoustic power generated by traffic volume
Authors: Bąkowski Andrzej , Radziszewski Leszek , Świetlik Paweł , Dekýš Vladimir
Published: January 2019

The concept of energy harvesting is a mechanism of deriving energy from the sources present in the environment. Using this energy will enable wireless and portable electronic devices to be completely self-sustaining. A variety of sources are available for energy harvesting, including electromagnetic radiation, vibration-, sound -, and windenergy. The output power levels from these sources and the mechanisms involved in energy conversion determine its possible applications. The paper analyses the variability of the acoustic power generated by traffic volume. The equivalent sound level was calculated by permanent automatic sound and traffic volume monitoring stations for three time intervals. The measurements were carried out 24 hours a day. In this study, the authors analysed the acoustic power to be able to compare the fixed and variable components. Standard deviation, coefficient of variation, the positional coefficient of variation, and the quartile deviation were proposed for performing a comparative analysis of the acoustic power scattering. The coefficient of variation is a parameter that satisfactorily describes a variable component of acoustic power. Uncertainties of the acoustic power calculation were compared within the periods under analysis.
A working design of a bulldozer blade as additional equipment of a compaction drum roller
Authors: Selech Jarosław , Ulbrich Dariusz , Włodarczyk Konrad , Staszak Żaneta , Marcinkiewicz Jacek , Romek Dawid , Baran Bartosz
Published: January 2019

The main purpose of the performed works was to develop a concept of a bulldozer blade mounted to the road roller. The paper presents the main assumptions, design stages, results of strength analyses of the blade, which can be used in a road roller. Because the elements that push the components of machines operating on construction sites, in mines and in the agricultural environment, the elaborated element would enable wider use of the roller. Based on the FEM analyses, it has been confirmed that the developed load bearing structure is characterized by full operating strength. The designed blade meets the initial assumptions and can be used as equipment of heavy machines.
The influence of geometry of primary air channels in standard retort burners on dust emission
Authors: Ciupek Bartosz , Bartoszewicz Jarosław
Published: January 2019

The article presents the analysis of dust emissions from a low power boiler fired with various solid fuels. The boiler, presented for testing, met the emission conditions for boilers made in the third class in accordance with the PN-EN 303-5: 2012 standard. The solid fuel boiler was equipped with two different retort burners with automatic fuel supply. For the test were used a first generation retort burner with a fixed rim and the next were used second generation retort burner provided with a rotary rim. Both constructions differ in the geometrical model of the primary air supply system to the furnace. During the tests, the work of the burners was controlled using a microprocessor temperature controller. During the research, the rotation time of the screw supplying the fuel through the retort to the furnace was changed, as well as the rotational speed of the blast fan impeller responsible for supplying the combustion air. The purpose of the tests was to check whether the boiler will meet the highest environmental class regardless of the technical parameters of the burner and fuel used. The article describes the research methodology and analysis of the results obtained. The effect of the tests carried out is a comparison of average dust emission values depending on the fuel used and the work settings of a given burner. The test results are a prerequisite for further research work in terms of the impact of primary air supply on the emission of harmful substances.
The influence of geometrical parameters of the forming channel on the boundary value of the axial force in the agglomeration process of dry ice
Authors: Górecki Jan , Malujda Ireneusz , Wilczyński Dominik
Published: January 2019

The article presents the results of study on the influence of geometrical parameters of the forming channels on axial force which is the main parameter of the agglomeration process of dry ice in the piston method. During research, the material was agglomerated utilizing different dies. The material is characterized by low temperature and sublimation under standard environmental conditions. The study focuses on determining the influence of geometrical parameters of the conical and cylindrical sections of the forming chamber which influence the value of yield stress in the carbon dioxide agglomeration process. The determination of the value of boundary force is the basis for formulating the construction assumptions which shall be the basis for designing and constructing the dry ice compaction and pelletization machine.
Effect of wave propagation and transfer of a sensor on detected acoustic emission signal
Authors: Raček Marek
Published: January 2019

One of the biggest challenge for acoustic emission (AE) signal classification on real constructions is transfer from laboratory measurement on specimens to full scale. Detected AE responses are (among other factors) strongly influenced by propagation of waves in material and transfer function of sensor used. Propagation of elastic stress waves in plate of AISI 304 stainless steel was investigated in this work. Two types of wave excitation were used: broad band HSU-Nielsen source and artificial narrow band source via Vallen VS150-M transducer. AE responses were detected with use of 3 different AE transducers to take into account the effect of sensor transfer function on detected response. Attenuation curves were constructed from extracted amplitudes and digitalized signal was recorded for subsequent advanced analysis. Description of detected wave modes and separation of reflected waves was successfully done with use of combination of voltage-time dependency, wavelet transform (WT) and dispersion curves. Effect of wave propagation and transfer function of a sensor on signal maximum amplitude was discussed.
Design of a cultivator mounted on a tractor with a power of up to 20 kW
Authors: Selech Jarosław , Ulbrich Dariusz , Kęska Włodzimierz , Staszak Żaneta , Marcinkiewicz Jacek , Romek Dawid , Rogoziński Przemysław
Published: January 2019

Cultivators are machines used among others to open and smooth out the surface of the ploughland and to mix mineral fertilizers with soil. The article presents a design of a cultivator mounted on an agricultural tractor with a power of up to 20 kW. The main design assumption mainly focuses on keeping the weight of the device low, while ensuring the required durability. Moreover, the design makes it possible to attach it to the three-point linkage in a category 1 tractor. The drafted design was subjected to the MES analysis, according to which, the maximum travel of the cultivator frame does not exceed 1.3 mm, and the stress typically reaches the level of 40 MPa and does not exceed the stress permissible for the E295 steel. An analysis of the costs of manufacturing the cultivator was also performed and on its basis, it was found that the price should not exceed PLN 1,800.
Empirical determination of the mechanical properties of Vacuum Packed Particles
Authors: Bartkowski Piotr , Zalewski Robert
Published: January 2019

In this work the experimental test of Vacuum Packed Particles (VPP) under 3-point bending are presented. VPP it is the structure compose of grains inside the plastomer coating. When the pressure inside is equal or higher than zero structure behave like a liquid, otherwise like a elasto-plastic solid. Three types of grain material and different values of underpressure were tested. Results presented in this paper will be used in the further work for the numerical model validation procedure.
Preliminary research of the thermomechanical properties of the round drive belts
Authors: Wałęsa Krzysztof , Mysiukiewicz Olga , Pietrzak Michał , Górecki Jan , Wilczyński Dominik
Published: January 2019

Most of the industrial machines use round-shaped drive belts for power transfer. These drive belts are often a few millimeters in diameter, and made of thermoplastic elastomer, especially polyurethane. Their production process requires the bonding step, which is often performed by hot plate butt welding. The authors have undertaken an effort to design an automatic welding machine, which calls for an analysis of the hot plate welding process consisting in describing the dependency between the technological parameters (temperature, pressure force, time) and the quality of the joint. To analyze this process in a proper way, it is necessary to describe the physical phenomena in the material during temperature and force impacts. In this case the research of thermomechanical properties of the belts is needed. The paper shows results of some preliminary research of the thermomechanical properties of the polyurethane. This research allows to predict the material reaction to increased temperature and force during hot plate welding.
The numerical analysis of the interaction between the low-order Lamb wave modes and surface breaking cracks
Authors: Šofer Michal , Ferfecki Petr , Fusek Martin , Šofer Pavel , Gnatowska Renata
Published: January 2019

Lamb waves, as one of the types of guided waves, are extensively used for inspecting large structures as well as for structure health monitoring applications. One of the biggest benefits of guided waves is their ability to travel over long distances without much attenuation. Lamb waves are often used for inspection of piping systems and similar geometries where the dimension in the third direction is significantly smaller than the other two. No wonder that the study of the interaction of Lamb waves with particular types of geometric discontinuities is a frequent topic of research. The main aim of the proposed paper is to present the findings related to the numerical study of the interaction between low-order Lamb wave modes and surface breaking crack oriented at different angles relative to the free surface.
A computational fluid dynamics investigation of the segmented integral squeeze film damper
Authors: Ferfecki Petr , Zapoměl Jaroslav , Gebauer Marek , Polreich Václav , Křenek Jiří
Published: January 2019

Rotor vibration attenuation is achieved with damping devices which work on different, often mutually coupled, physical principles. Squeeze film dampers are damping devices that have been widely used in rotordynamic applications. A new concept of a 5-segmented integral squeeze film damper, in which a flexure pivot tilting pad journal bearing is integrated, was investigated. The damper is studied for the eccentric position between the outer and inner ring of the squeeze film land. The ANSYS CFX software was used for solving the pressure and velocity distribution. The development of the complex three-dimensional computational fluid dynamics model of the squeeze film damper, learning more about the effect of the forces in the damper, and the knowledge about the behaviour of the flow are the principal contributions of this article.
Prevention of canine ocular thelaziosis (Thelazia callipaeda) with a combination of milbemycin oxime and afoxolaner (Nexgard Spectra®) in endemic areas in France and Spain
Authors: Lebon Wilfried , Guillot Jacques , Álvarez Maria-Jesús , Antonio Bazaga José , Cortes-Dubly Marie-Laure , Dumont Pascal , Eberhardt Marianne , Gómez Héctor , Pennant Olivier , Siméon Noémie , Beugnet Frederic , Halos Lénaïg
Published: January 2019

In the past decade, canine thelaziosis due to Thelazia callipaeda has been diagnosed in an increasing number of European countries, with endemic areas being identified. A multi-center field trial was conducted in endemic areas in France and Spain to evaluate the efficacy of monthly administrations of the oral milbemycin oxime/afoxolaner combination (NexGard Spectra®) for the prevention of T. callipaeda infection in at-risk dogs. A total of 79 dogs negative for T. callipaeda and with a clinical history of eyeworm infection in the past two years completed the study. Dogs were randomly allocated either to a negative control group (42 dogs) or to the NexGard Spectra® treated group (37 dogs). All dogs were followed up for a 6-month period and assessed monthly for the presence of nematodes on the eyes and for the signs of ocular thelaziosis (e.g., conjunctivitis, keratitis, and ocular discharge). When the presence of nematodes was confirmed, the conjunctival fornix was flushed with a saline solution for parasite recovery and counting, and the dogs were treated appropriately. Recovered parasites were stored in 70% alcohol for subsequent morphological identification. During the course of the study, 57.1% (24/42) of the control dogs were diagnosed positive for Thelazia infection, which illustrates a high incidence rate of parasite infection. Conversely, no eyeworm was recovered from any of the 37 dogs that received NexGard Spectra®. All parasites sampled were confirmed to be T. callipaeda. This clinical field study demonstrated that monthly administrations of NexGard Spectra® provided 100% preventive efficacy against canine thelaziosis.
Effect of laser beam size on the dynamics of ultrashort laser-produced aluminum plasma in vacuum
Authors: Sankar Pranitha , Shashikala H. D. , Philip Reji
Published: January 2019

In laser-produced plasma experiments, the diameter of the irradiating laser beam on the target surface is a major parameter that influences the ablation mechanisms, plasma emission intensity, charged particle ejection, and plume morphology. In this work, the expansion dynamics of an ultrashort laser-produced aluminum plasma is investigated as a function of the laser beam size on the target, using a combination of diagnostic tools, viz., optical emission spectroscopy, fast gated time-resolved imaging, and ion current measurements. A Ti:sapphire laser delivering 100 fs, 6 mJ pulses at 800 nm is used for producing plasma from a pure Al target placed in vacuum (10−5 Torr) at different positions with respect to the geometrical focus of the beam. Optical emission spectroscopic analysis of the plasma shows that higher emission intensities and ion populations are obtained for smaller beam sizes. Time-resolved Intensified Charge Coupled Device (ICCD) imaging of the expanding plasma shows a spherical morphology for plumes produced by smaller beam sizes and a cylindrical morphology for those produced by larger beam sizes. Temporal profiles of ion emission measured using a Faraday cup are in agreement with ICCD data, featuring a dual peak structure for larger beam sizes indicating distinct slow and fast ionic species, arising from changes in the ablation mechanism for varying laser fluences. Plume expansion is modelled by free expansion for the fast species and by shock wave propagation for the slow species. Ion flux and velocities are relatively high for smaller beam sizes. These studies can be of potential importance for laser processing applications, including laser welding, drilling, and micromachining.