bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure Strain and Strain-Stress Analysis in Titanium Nitride Coatings Deposited on Religa Heart Ext Ventricular Assist Device
Authors: Kopernik M. 
Published: April 2015

AbstractThe Polish ventricular assist device is made of Bionate II with deposited TiN biocompatible nano-coating. The two scale finite element model is composed of a macro-model of blood chamber and a micro-model of the TiN/Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture. Therefore, the identification of a fracture parameter considered as a failure strain is the purpose of the present work. The tensile test in a micro chamber of the SEM was performed to calibrate the fracture parameter of the material system TiN/Bionate II. The failure strain is a function of a temperature, a thickness of coating and parameters of surface's profile. The failure strain was calculated at the stage of the test, in which the initiation of fracture occurred. The finite element micro-model includes the surface roughness and the failure strain under tension condition for two thicknesses of coatings which will be deposited on the medical device.
Microstructure of Cast Ni-Cr-Al-C Alloy
Authors: Cios G. , Bała P. , Stępień M. , Górecki K. 
Published: April 2015

Abstract
Nickel based alloys, especially nickel based superalloys have gained the advantage over other alloys in the field of high temperature applications, and thus become irreplaceable at high temperature creep and aggressive corrosion environments, such as jet engines and steam turbines. However, the wear resistance of these alloys is insufficient at high temperatures. This work describes a microstructure of a new cast alloy. The microstructure consists of γ matrix strengthened by γ’ fine precipitates (dendrites) improving the high temperature strength and of Chromium Cr7C3 primary carbides (in interdendritic eutectics) which are designed to improve wear resistance as well as the high temperature strength.
Part III. Kinetics of the (Zn) - Coating Deposition During Stable and Meta-Stable Solidifications
Authors: Wołczyński W. , Kucharska B. , Garzeł G. , Sypień A. , Pogoda Z. , Okane T. 
Published: April 2015

Abstract
Two different steel substrates are applied to the hot dip (Zn) - coating formation. The influence of the substrate composition on the (Zn) - coating thickening is recorded. Morphologies of both coatings are compared to each other. The transition from stable into meta-stable solidification is revealed. The criterion for the competition between stable and meta-stable solidification is applied to justify the analyzed transition.
Investigation of the Flow Structure in the Tundish with the Use of Rans and Les Methods
Authors: Warzecha M. , Merder T. , Warzecha P. 
Published: April 2015

AbstractThe liquid steel flow structure in the tundish has a very substantial effect on the quality of the final product and on efficient casting conditions. Numerous model studies are being carried out to explain the effect of the tundish working conditions on casting processes.It is necessary to analyze the structure of liquid steel flow, which is strongly supported with numerical modeling. In numerical modeling, a choice of a proper turbulence model is crucial as it has a great impact on the flow structure of the fluid in the analyzed test facility. So far most numerical simulations has been done using RANS method (Reynolds-averaged Navier-Stokes equations) but in that case one get information about the averaged values of the turbulent flow. In presented study, numerical simulations using large eddy simulations (LES) method were used and compared to RANS results. In both cases, numerical simulations are carried out with the finite-volume commercial code AnsysFluent.
Effect of Temperature Fields Heterogeneity in the Tundish on Primary Structure of Continuously Cast Ingots
Authors: Pieprzyca J. , Kudliński Z. , Merder T. 
Published: April 2015

AbstractThe formation of the cast strands’ primary structure is a very complex process in terms of the thermodynamics and physicochemical. It occurs during solidification and crystallization of the liquid steel in the crystallizer and in the secondary cooling zone of the CC device. On the basis of the experience gained in the industry and knowledge arising from theory of metals and alloys solidification it can be concluded, that substantial influence on the shape of cast strands primary structure have the temperature of overheating of the liquid steel above liquidus temperature and solidification velocity. A proper control of those casting parameters allows to obtain the cast strands with desired primary structure. In the one and two-way symmetric devices regulation like this is not problematic, in the multi-way devices - specially in the asymmetric - causes a series of problems. In those devices can occur a major temperature difference in each outlet zone of the tundish working space caused by i.e. the distance length diversity of liquid steel stream from the inlet to each outlet and by disadvantageous layout of liquid steel flow zones (turbulent flow zone, plug flow and dead zones) in working area of tundish. Particularly high values of those diversity can be expected in the asymmetric tundishes.The article presents results of laboratory research - model and industrial regarding impact of the liquid steel overheating temperature, but also heterogeneity of the temperature fields in the tundish on primary structure of the cast strands.
Improving Efficiency of CCS Numerical Simulations Through Use of Parallel Processing
Authors: Konopka K. , Miłkowska-Piszczek K. , Trębacz L. , Falkus J. 
Published: April 2015

Abstract
The study presents the findings of research concerning the possibilities for application of parallel processing in order to reduce the computing time of numerical simulations of the steel continuous casting process. The computing efficiency for a CCS model covering the mould and a strand fragment was analysed. The calculations were performed with the ProCAST software package using the finite element method. Two computing environments were used: the PL-Grid infrastructure and cloud computing platform.
Method for Determining the Time Constants Characterizing the Intensity of Steel Mixing in Continuous Casting Tundish
Authors: Pieprzyca J. , Jowsa J. 
Published: April 2015

AbstractA common method used in identification of hydrodynamics phenomena occurring in Continuous Casting (CC) device's tundish is to determine the RTD curves of time. These curves allows to determine the way of the liquid steel flowing and mixing in the tundish. These can be identified either as the result of numerical simulation or by the experiments - as the result of researching the physical models. Special problem is to objectify it while conducting physical research. It is necessary to precisely determine the time constants which characterize researched phenomena basing on the data acquired in the measured change of the concentration of the tracer in model liquid's volume. The mathematical description of determined curves is based on the approximate differential equations formulated in the theory of fluid mechanics. Solving these equations to calculate the time constants requires a special software and it is very time-consuming. To improve the process a method was created to calculate the time constants with use of automation elements. It allows to solve problems using algebraic method, which improves interpretation of the research results of physical modeling.
Multiphase Numerical Model of Molten Steel and Slag Behavior in the Continuous Casting Mould
Authors: Bielnicki M. , Jowsa J. , Cwudziński A. 
Published: April 2015

AbstractThe paper reports the results of numerical simulation of the flow of liquid steel with the use of a multiphase model. The facility under study was a mould designed for continuous casting of steel slabs. The geometry of the facility, along with the computational grid, was generated within the program Ansys-MeshingR. Numerical computations were performed in the programs: COMSOL Multiphysics¯ and Ansys-Fluent¯. The use of the multiphase model enabled the determination of the behavior of the liquid slag layer on the metal bath surface. From the performed computer simulations, the fields of liquid steel motion and liquid steel turbulence kinetic energy distribution in the mould's symmetry plane have been presented. Based on the values recorded at selected measurement points located on the slag surface, a diagram illustrating the variation of the slag layer position during continuous steel casting has been plotted.
Interaction Between Steel Melt and Refractory Materials in Tundish
Authors: Drofelnik N. , Lamut J. , Marolt M. , Knap M. 
Published: April 2015

Abstract
In Štore Steel steelworks steel is casted on a three strand continuous casting machine. Lining of tundish is mainly made from a magnesia based material. Tundish cover powder is based on alumina and silica. It also contains aluminum and carbon.
During casting, the composition of cover slag is constantly changing. When steel in casted in sequences the change in cover slag composition depends on the amount of CaO rich ladle slag. The composition of tundish cover slag at the end of the casting sequence lies in the area of gehlenite (2CaO·Al2O3·SiO2) in ternary phase diagram CaO·Al2O3·SiO2.
The result of the reaction between melted steel, refractory material and tundish cover slag are enstatite (MgO·SiO2) and monticellite (CaO·MgO·SiO2). Merwinite (3CaO·MgO·SiO2) is formed in the end of the casting sequence because of high basicity of the gehlenite based tundish cover slag.
Clogging on the inner side of submerged entry nozzles (SEN) are made of calcium aluminates (CaO·2Al2O3) and spinel (MgO, MnO)·Al2O3. Only when steel is casted in sequence composition changes in tundish cover slag and clogging occurs.
Influence of the Radiation Shield on the Temperature of Rails Rolled in the Reversing Mill
Authors: Gołdasz A. , Malinowski Z. , Hadała B. , Rywotycki M. 
Published: April 2015

AbstractThe paper presents a mathematical model of heat transfer during cooling of hot-rolled rails in the reversing mill. The influence of the radiation shield on the temperature of rolled rails has been analyzed. The heat transfer model for cooling a strip covered by the thermal shield has been presented. The two types of shields build of steel and aluminum sheets separated with insulating layer have been studded. Calculations have been performed with self developed software which utilizes the finite element method.
Changes in Hydrogen Content During Steelmaking
Authors: Vrbek K. , Lamut J. , Marolt M. , Knap M. 
Published: April 2015

Abstract
Štore Steel produces steel grades for spring, forging and engineering industry applications. Steelmaking technology consists of scrap melting in Electric Arc Furnace (EAF), secondary metallurgy in Ladle Furnace (LF) and continuous casting of billets (CC). Hydrogen content during steelmaking of various steel grades and steelmaking technologies was measured. Samples of steel melt from EAF, LF and CC were collected and investigated. Sampling from Electric Arc Furnace and Ladle Furnace was carried out using vacuum pin tubes. Regular measurements of hydrogen content in steel melt were made using Hydris device. Hydrogen content results measured in tundish by Hydris device were compared with results from pin tube samples. Based on the measurement results it was established that hydrogen content during steelmaking increases. The highest values were determined in tundish during casting. Factors that influence the hydrogen content in liquid steel the most were steelmaking technology and alloying elements.
Ecological Aspects of the Performed Thermal Reclamation
Authors: Łucarz M. 
Published: April 2015

AbstractThe thermal analysis results of the selected group of binders and the thermal reclamation of one spent moulding sand with organic binder, are presented in the paper. The reclaiming process of the quartz matrix was performed on the basis of the own method of selecting the reclamation temperature. Taking into account thermogravimetric (TG) analysis results of the binder, the temperature range - required for performing the efficient reclamation of spent moulding sand containing this binder - was indicated. In order to confirm the assumptions, the thermal reclamation operations were carried out at a temperature similar to the determined on the TG basis and - for comparisons - at lower and higher temperatures. During the reclamation operation the reclaim samples were taken for the loss on ignition testing, aimed at the determination of the process efficiency. Temperature in the reclaimer chamber and gas consumptions were also recorded. On the bases of the thermal analyses, loss on ignition, gas consumption and temperatures of the reclaimed moulding sand bed the recommendations for the realisation of the thermal reclamation were given. These recommendations will allow a better, than currently available, process control in an aspect of decreasing the pyrolysis effect and limiting the emission of substances harmful for the environment.
Thermal Conductivity of Moulding Sand with Chemical Binders, Attempts of its Increasing
Authors: Zych J. , Mocek J. , Snopkiewicz T. , Jamrozowicz Ł. 
Published: April 2015

Abstract
The investigation results of the thermal conductivity of the selected group of moulding sands with chemical binders, mainly organic, are presented in the hereby paper. Studies encompassed also moulding sands into which additions improving the thermal conductivity were introduced. Two testing methods were applied, i.e. investigations at a steady and unsteady temperature zone. For investigations at a steady temperature zone the new original experimental stand was designed and built, adapted also for testing moulding sands with binders undergoing destruction at relatively low temperatures.
The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions
Authors: Suliga M. 
Published: April 2015

Abstract
In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estimated.
It has been shown that in the drawing process under hydrodynamic lubrication by drawing speed of 25 m/s the phenomena of uncontrolled formation of the surface and the diameter of the wire appears, and in the process the compressive stresses eliminating cracks on the wire surface occur, causing further smoothing. The wires drawn hydrodynamically in speed of 25 m/s, besides clearly worse properties compared to the wires drawn hydrodynamically at speeds in the range of 5 to 20 m/s, also exhibit large dimensional variations.
Numerical Analysis of the Cross-Wedge Rolling Process by Means of Three Tools of Stepped Shafts From Aluminum Alloy 7075
Authors: Bartnicki J. , Tomczak J. , Pater Z. 
Published: April 2015

Abstract
This paper presents results of numerical calculations for the rolling process by means of three tools of stepped shafts from aluminum alloy 7075. Forming with the usage of tools with three different wedge spreading angles underwent analysis. In the paper, the obtained distributions of stresses, strains and Cockcroft-Latham damage criterion were given. Moreover, the influence of the wedge spreading angle on shape faults presence in the obtained product was determined. At the same time, the force parameters, which play a crucial role in the designed experiment, were analyzed.
Design of Controlled Processing Conditions for Drop Forgings Made of Microalloy Steel Grades for Mining Industry
Authors: Skubisz P. , Żak A. , Burdek M. , Lisiecki Ł. , Micek P. 
Published: April 2015

Abstract
Effect of plastic processing and controlled cooling on microstructure and mechanical properties of experimental steel grades with microalloyed with Ti, V and/or Nb, varying in the content of Mo is presented as an offer for mining industry for replacement traditionally heat-treatable hardenability grades. The goal of the work is producing microstructure condition, which after controlled hot forging and direct heat treatment, involving quenching and self-tempering, are meant to provide good combination of mechanical properties, such as TYS 800 MPa, UTS 1050 MPa, elongation to fracture at least A5 15% and/or impact strength at room temperature KCV 60 J/cm2. Hardenability assessment and dilatometric examination allowed formulation of direct heat treatment guidelines, taking into consideration fields of temperature and strain in a typical hot forging process, estimated numerically, with the use of plastometric tests results, as well as the use of unique cooling cycles after forging.
On the basis of numerical analysis of thermomechanical parameters and temperature progression, hot forging and direct cooling conditions were selected to achieve assumed structural components, morphology and dispersion of both grain and precipitates. For established heat transfer model and experimentally plotted cooling curves numerical analysis of direct cooling, enabled by definition of characteristic points of austenite transformation and CCT diagrams was conducted. The modeling aided with dilatometric characterization enabled prediction of transformation products distribution. The formulated conclusions were verified in the experimental sampling of forging, evaluating the applicability of designed combinations of chemical composition and cooling cycle for selected forged part for mining industry.
The Effect of Stepped Austempering on Phase Composition and Mechanical Properties of Nanostructured X37CrMoV5-1 Steel
Authors: Marciniak S. , Skołek E. , Świątnicki W. 
Published: April 2015

AbstractThis paper presents the results of studies of X37CrMoV5-1 steel subjected to quenching processes with a one-step and a two-step isothermal annealing. The TEM observation revealed that steel after one-step treatment led is composed of carbide-free bainite with nanometric thickness of ferrite plates and of high volume fraction of retained austenite in form of thin layers or large blocks. In order to improve the strength parameters an attempt was made to reduce the austenite content by use of quenching with the two-step isothermal annealing. The temperature and time of each step were designed on the basis of dilatometric measurements. It was shown, that the two-step heat treatment led to increase of the bainitic ferrite content and resulted in improvement of steel's strength with no loss of steel ductility.
Guidance, Navigation and Control of Unmanned Surface Vehicles
Authors: Kurowski Martin , Haghani Adel , Koschorrek Philipp , Jeinsch Torsten 
Published: April 2015

Abstract
In this paper, a framework for guidance, navigation and control of marine vehicles is proposed. The focus is on application of unmanned
surface vehicle for performing high accuracy measuring tasks. The desired maneuvering path is defined as a combination of standard
path sections and delivered to the guidance system. The measurements are filtered and the unmeasurable states are estimated in
navigation system and fed back to the guidance and control systems. An extended Kalman filter based approach is used in navigation
system, in order to take the nonlinear behaviors of the system into consideration. The proposed control scheme is a modular system
consisting of a cascade structure, where the unified inner loop is responsible for velocity control and the outer loop can be adapted
independently to various missions. The model parameters are estimated based on subspace identification method using data obtained from
a measuring vehicle, MESSIN. The results have been further used for design of control and navigation systems. The performance and
effectiveness of the proposed framework are demonstrated on a model for a path following mission.
Guidance of AUVs for Autonomous Underwater Inspection
Authors: Jacobi Marco , Karimanzira Divas 
Published: April 2015

Abstract
In this paper, a task-based online path-planning and guidance system of underactuated unmanned underwater vehicles (UUVs) for
inspection of underwater infrastructure is described. Whether there are harbor submerged structures, cables, pipes, hydro-technical
works, they all need to be checked in relation to structural deterioration specific potential problems such as scour, erosion, and
accelerated local corrosion problems. At the highest level, the mission controller handles different event types, permitting also the
execution of mission tasks. The online path-planning module generates a set of waypoints based on an environmental perception module
for the AUV to follow the target object with a constant distance. The guidance method actually controls the vehicle to follow the
waypoints, assuming the relative position and attitude of the vehicle is precisely estimated in real-time. By combining these methods,
an AUV can perform fully autonomous inspection of underwater structures. The system was evaluated with success for several harbor and
pipeline inspection scenarios in a test basin and sea trials.
Dietary intake of specific phenolic compounds and their effect on the antioxidant activity of daily food rations
Authors: Koch Wojciech , Baj Tomasz , Kukula-Koch Wirginia , Marzec Zbigniew 
Published: April 2015

Abstract
The determination of phenolic acids’ and flavonoids’ content in daily food rations (DFRs) of
a selected group of male and female students and the development of chromatographic conditions is the primary goal of the study. The presence of 7 phenolic components were confirmed in the prepared extracts from all diets reconstructed within a period of 3 years. The highest concentrations were determined for hesperidin (124 and 55.6 mg for women and men, respectively), naringin
(47.6 mg in female and 37 mg in male diets) and chlorogenic acid (19.7 and 19.8 mg for women and men). The antioxidant potential of the daily food rations, measured with
a DPPH test, was higher for women (range 47.1‒78.8%) than for men (range 34.5‒78.0%) and was found to strongly correlate with the total phenolics content of the samples (Folin-Ciocalteu test) (correlation coefficient 0.90).
Anisotropy Effects on the Thermoelectric Electronic Transport Coefficients
Authors: Mecholsky Nicholas A. , Hamad Bothina , Resca Lorenzo , Pegg Ian L. , Fornari Marco 
Published: April 2015

Abstract
Engineering thermoelectric (TE) materials for applications in power generation and cooling requires an understanding of how anisotropy influences the TE properties. In this paper we use an angular-dependent, multivalley formalism to model the band structure and to explore the effect of anisotropy on the Seebeck and conductivity tensors. Specifically we explore the effect of degeneracy and relative orientation of the effective mass ellipsoids near critical points on the shape of these tensors. Examples of these types of anisotropic effects are explored within the above formalism and with the full band structures of two materials: half-Heusler ZrNiSn and (Sr,Ba)Nb2O6 with the tetragonal tungsten bronze structure.
Abel dynamic equations of first and second kind
Authors: Bohner Martin , Streipert Sabrina H. 
Published: April 2015

Abstract
This paper gives the definition and analysis of
Abel dynamic equations on a general time scale.
As such, the results contain as special cases
results for classical Abel differential equations
and results for new Abel difference equations.
By using appropriate transformations,
expressions of Abel dynamic equations of
second kind are derived on the general time scale.
This also leads to a specific class of
Abel dynamic equations of first kind.
Finally, the canonical Abel dynamic equation
is defined and examined.