bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vivo Enzymes Activities of Some Ru(II) Compounds with N-Alkylphenothiazines
Authors: Krstić P. Milena , Borozan Z. Sunčica , Sovilj P. Sofija , Grgurić-Šipka R. Sanja , Oljarević M. Jelena
Published: January 2017

The purpose of the present study was to investigate and compare the effects of two ruthenium complexes with trifluoperazine on acethylcholinesterase enzyme activity and lactate dehydrogenase levels in vivo under physiological conditions in rats blood. Complexes 1 and 2 showed positive effects on acethylcholinesterase at all doses and did not disturb its normal activity. Total LDH activity was inhibited in the presence of both complexes, but Ru(II) complexes showed different effects on the activity of LDH isoenzymes. The activities of LDH1 and LDH2 isoenzymes were decreased in all applied doses of the complex 2, while the activity of LDH2 reduced using complex 1 in the same doses. Results of the present study suggest the neuro- and cardio protective potential of oral administration of complexes 1 and 2, as non-toxic compounds under physiological conditions. These protective effects are the result of their potent antioxidant activity.
Isolation and Molecular Detection of Bovine Parainfluenza Virus Type 3 in Cattle in Serbia
Authors: Veljović Ljubiša , Knežević Aleksandra , Milić Nenad , Krnjaić Dejan , Miković Radoš , Zorić Andrea , Marković Maja , Milićević Vesna , Stamenković Miodrag , Stanojević Maja , Maksimović-Zorić Jelena , Petrović Tamaš , Nišavić Jakov
Published: January 2017

The presence of bovine parainfluenza virus type 3 (BPIV3) was examined in 119 nasal swabs collected from cattle with severe respiratory infection. All samples were conducted for virus isolation on the MDBK cell line. The cytopathic effect was observed after 48h to 72h in cells inoculated with eight samples (8/119; 6.7%). The confirmation of isolated strains of BPIV3 was done by the virus-neutralization test. In addition, all samples of bovine nasal swabs were also examined for the presence of BPIV3 virus using RT-PCR with primers specific for the part of HN gene. The presence of BPIV3 was detected in eight samples (8/119; 6.7%) that were also positive upon virus isolation. The molecular characterization based on nucleotide sequencing of the part of the HN gene showed that all BPIV3 isolates belonged to genotype C of BPIV3. They branched in one distinct cluster with three different branches, but these branches were very similar to each other (98.1% to 99.8%). Serbian BPIV3c isolates were most similar to the Chinese BPIV3c isolates SD0805, SD0809 and SD0835 (from 97.92% to 99.7%), and to South Korean (12Q061), Japanese (HS9) and American (TVMDL16 and TVMDL20) BPIV3c strains (from 97.1% to 98.8%), and distinct from American (TVMDL15and TVMDL17) and Australian (Q5592) BPI3V genotype B strains (only 79.9% to 82.3% similarity), as well as from the genotype A BPIV3 strains from different countries published in GenBank.
Molecular Characterization of ESBL-Producing Escherichia Coli Isolated from Healthy Cattle and Sheep
Authors: Pehlivanoglu Faruk , Turutoglu Hulya , Ozturk Dilek , Yardimci Hakan
Published: January 2017

The present study aims to characterize ESBL-producing Escherichia coli isolated from healthy cattle and sheep in the Burdur province of Turkey. Fecal samples from a total of 200 cattle and 200 sheep were tested and ESBL-producing E. coli was isolated from 31 (15.5%) cattle and three (1.5%) sheep samples using the Clinical and Laboratory Standards Institute’s combined disk method. Among the ESBL gene classes detected by PCR, blaCTX-M was the most frequent type, followed by the blaTEM and blaSHV families. ESBL-producing E. coli isolates showed co-resistance to multiple classes of antibiotics including aminoglycosides, phenicols, quinolones, folate pathway inhibitors and tetracyclines. The resistance rates were higher in the cattle isolates than in the sheep isolates. Phylogenetic grouping of the E. coli isolates indicated group A (particularly A1) was the predominant phylogenetic group (19/34, 55.9%), followed by groups B1 (9/34, 26.5%) and D (6/34, 17.6%); none of the isolates belonged to group B2. The study shows that ESBL-producing E. coli isolates exist in the intestinal flora of healthy cattle and sheep in the Burdur province of Turkey. This is the first report showing the emergence of CTX-M type ESBL-producing E. coli in sheep farms in Turkey
Plasma Total Antioxidant Capacity and Activities of Blood Glutathione Peroxidase and Superoxide Dismutase Determined in Healthy Dogs by Using Commercially Available Kits
Authors: Tomsič Katerina , Seliškar Alenka , Lukanc Barbara , Nemec Svete Alenka
Published: January 2017

Data on the values of selected blood antioxidant parameters, i.e. total antioxidant capacity, glutathione peroxidase, and superoxide dismutase in healthy dogs, are lacking. There are no published accepted standard reference methods for their determination. The aim of this study was to determine the values of plasma total antioxidant capacity and the activities of whole blood glutathione peroxidase and erythrocyte superoxide dismutase in 30 healthy client-owned dogs (19 females, 11 males). The effect of age and sex on the measured antioxidant parameters was also investigated. Antioxidant parameters were determined with an automated biochemical analyser, using the commercially available Randox kits. No significant difference in age, weight, and antioxidant parameters was determined between females and males. A significant positive effect of age (p = 0.002, r2= 0.284) on superoxide dismutase activity was confirmed. There was no effect of sex on any of the antioxidant parameters measured. However, we observed a tendency of the effect of sex (p = 0.063, r2= 0.118), as well as age (p = 0.073, r2= 0.111), on the activity of glutathione peroxidase. Our results are in part comparable with the results of other studies in which the same types of methods and samples were used to determine antioxidant parameters. In conclusion, the sex and age of dogs should be taken into consideration when planning a study on antioxidant status parameters.
Malignant Pilomatricoma in a Young Dog
Authors: Lee Eun-Joo , Ah-Young Kim , Eun-Mi Lee , Jin-Kyu Park , Kyu-Shik Jeong
Published: January 2017

Malignant pilomatricoma is malignant follicular tumor with only matrical differentiation. Malignant pilomatricoma is rare in dogs. There is little information about sex, breed and age predisposition. There are a few reports of canine malignant pilomatricoma in middle to old age dogs. However, this neoplasm was resected from 1-year-old intact male miniature poodle. The neoplasm was found in the dorsal part of the neck. The mass was firm and protruded. On gross findings the size of the mass was 3×2×1.5cm. The mass was located in the deep dermis and subcutaneous layer. The mass was composed of several lobules of grey-white chalky material. Microscopically, the mass was composed of several large and small lobules. There were basophilic round to oval basaloid cells at the periphery of the lobules. The basophilic cells showed abrupt keratinization. Numerous ghost cells were observed in the center of the mass. The ghost cells had abundant eosinophilic cytoplasm without a nucleus. The basophilic basaloid cells showed numerous atypical mitotic figures. Cellularity was high and pleomorphism was remarkable. No lymphatic metastasis was observed. We reported a rare case of malignant pilomatricoma in a 1-year-old young dog.
The development of conflict resolution practices in Irish workplaces
Authors: Roche William K.
Published: January 2017

This paper examines the development of procedures for conflict resolution in workplaces in Ireland and the more recent emergence of alternative dispute resolution (ADR) practices. Based on a synthesis of data from a series of studies and on a review of reports of conflict resolution innovations, the paper shows how conventional procedures for resolving collective disputes and individual employment grievances had become almost standard by the 1980s, while a series of ADR practices became features of conflict resolution from the 1990s. The changing character of conflict resolution procedures and practices is attributed to a series of influences that include the professionalisation of personnel and human resource management, the changing pattern and context of workplace conflict, the growing importance of multinational firms, and the emergence of professional training and expertise in the provision of ADR support services. The paper projects a continuing rise in the incidence and use of ADR practices but questions the extent to which organisations in Ireland are likely to adopt conflict management systems based on integrated sets of conflict resolution practices.
A dynamically adaptive lattice Boltzmann method for thermal convection problems
Authors: Feldhusen Kai , Deiterding Ralf , Wagner Claus
Published: January 2017

Utilizing the Boussinesq approximation, a double-population incompressible thermal lattice Boltzmann method (LBM) for forced and natural convection in two and three space dimensions is developed and validated. A block-structured dynamic adaptive mesh refinement (AMR) procedure tailored for the LBM is applied to enable computationally efficient simulations of moderate to high Rayleigh number flows which are characterized by a large scale disparity in boundary layers and free stream flow. As test cases, the analytically accessible problem of a two-dimensional (2D) forced convection flow through two porous plates and the non-Cartesian configuration of a heated rotating cylinder are considered. The objective of the latter is to advance the boundary conditions for an accurate treatment of curved boundaries and to demonstrate the effect on the solution. The effectiveness of the overall approach is demonstrated for the natural convection benchmark of a 2D cavity with differentially heated walls at Rayleigh numbers from 103up to 108. To demonstrate the benefit of the employed AMR procedure for three-dimensional (3D) problems, results from the natural convection in a cubic cavity at Rayleigh numbers from 103up to 105are compared with benchmark results.
A metaheuristic for a numerical approximation to the mass transfer problem
Authors: Avendaño-Garrido Martha L. , Gabriel-Argüelles José R. , Quintana-Torres Ligia , Mezura-Montes Efrén
Published: January 2017

This work presents an improvement of the approximation scheme for the Monge-Kantorovich (MK) mass transfer problem on compact spaces, which is studied by Gabriel et al. (2010), whose scheme discretizes the MK problem, reduced to solve a sequence of finite transport problems. The improvement presented in this work uses a metaheuristic algorithm inspired by scatter search in order to reduce the dimensionality of each transport problem. The new scheme solves a sequence of linear programming problems similar to the transport ones but with a lower dimension. The proposed metaheuristic is supported by a convergence theorem. Finally, examples with an exact solution are used to illustrate the performance of our proposal.
The use of a non-integer order PI controller with an active queue management mechanism
Authors: Domański Adam , Domańska Joanna , Czachórski Tadeusz , Klamka Jerzy
Published: January 2017

In this paper the performance of a fractional order PI controller is compared with that of RED, a well-known active queue management (AQM) mechanism. The article uses fluid flow approximation and discrete-event simulation to investigate the influence of the AQM policy on the packet loss probability, the queue length and its variability. The impact of self-similar traffic is also considered.
Set-membership identifiability of nonlinear models and related parameter estimation properties
Authors: Jauberthie Carine , Travé-MassuyèEs Louise , Verdière Nathalie
Published: January 2017

Identifiability guarantees that the mathematical model of a dynamic system is well defined in the sense that it maps unambiguously its parameters to the output trajectories. This paper casts identifiability in a set-membership (SM) framework and relates recently introduced properties, namely, SM-identifiability, μ-SM-identifiability, and ε-SM-identifiability, to the properties of parameter estimation problems. Soundness and ε-consistency are proposed to characterize these problems and the solution returned by the algorithm used to solve them. This paper also contributes by carefully motivating and comparing SM-identifiability, μ-SM-identifiability and ε-SM-identifiability with related properties found in the literature, and by providing a method based on differential algebra to check these properties.
Fault isolability with different forms of the faults–symptoms relation
Authors: Kóscielny Jan Maciej , Syfert Michał , Rostek Kornel , Sztyber Anna
Published: January 2017

The definitions and conditions for fault isolability of single faults for various forms of the diagnostic relation are reviewed. Fault isolability and unisolability on the basis of a binary diagnostic matrix are analyzed. Definitions for conditional and unconditional isolability and unisolability on the basis of a fault information system (FIS), symptom sequences and directional residuals are formulated. General definitions for conditional and unconditional isolability and unisolability in the cases of simultaneous evaluation of diagnostic signal values and a sequence of symptoms are provided. A comprehensive example is discussed.
Performance evaluation of an M/G/n-type queue with bounded capacity and packet dropping
Authors: Tikhonenko Oleg , Kempa Wojciech M.
Published: January 2017

A queueing system of the M/G/n-type, n ≥ 1, with a bounded total volume is considered. It is assumed that the volumes of the arriving packets are generally distributed random variables. Moreover, the AQM-type mechanism is used to control the actual buffer state: each of the arriving packets is dropped with a probability depending on its volume and the occupied volume of the system at the pre-arrival epoch. The explicit formulae for the stationary queue-size distribution and the loss probability are found. Numerical examples illustrating theoretical formulae are given as well.
Lookahead selective sampling for incomplete data
Authors: Abdallah Loai , Shimshoni Ilan
Published: January 2017

Missing values in data are common in real world applications. There are several methods that deal with this problem. In this paper we present lookahead selective sampling (LSS) algorithms for datasets with missing values. We developed two versions of selective sampling. The first one integrates a distance function that can measure the similarity between pairs of incomplete points within the framework of the LSS algorithm. The second algorithm uses ensemble clustering in order to represent the data in a cluster matrix without missing values and then run the LSS algorithm based on the ensemble clustering instance space (LSS-EC). To construct the cluster matrix, we use the k-means and mean shift clustering algorithms especially modified to deal with incomplete datasets. We tested our algorithms on six standard numerical datasets from different fields. On these datasets we simulated missing values and compared the performance of the LSS and LSS-EC algorithms for incomplete data to two other basic methods. Our experiments show that the suggested selective sampling algorithms outperform the other methods.
The impatience mechanism as a diversity maintaining and saddle crossing strategy
Authors: Karcz-Duleba Iwona
Published: January 2017

The impatience mechanism diversifies the population and facilitates escaping from a local optima trap by modifying fitness values of poorly adapted individuals. In this paper, two versions of the impatience mechanism coupled with a phenotypic model of evolution are studied. A population subordinated to a basic version of the impatience mechanism polarizes itself and evolves as a dipole centered around an averaged individual. In the modified version, the impatience mechanism is supplied with extra knowledge about a currently found optimum. In this case, the behavior of a population is quite different than previously-considerable diversification is also observed, but the population is not polarized and evolves as a single cluster. The impatience mechanism allows crossing saddles relatively fast in different configurations of bimodal and multimodal fitness functions. Actions of impatience mechanisms are shown and compared with evolution without the impatience and with a fitness sharing. The efficiency of crossing saddles is experimentally examined for different fitness functions. Results presented in the paper confirm good properties of the impatience mechanism in diversity maintaining and saddle crossing.
Gas Evolution Rates of Graphite Protective Coatings in Dependence on the Applied Solvent and Kind of Atmosphere
Authors: Kmita A. , Drożyński D. , Mocek J. , Roczniak A. , Zych J. , Holtzer M.
Published: January 2017

The results concerning emission of gases from two commercial graphite protective coatings for moulds and cores (water and alcoholic) are given in the hereby paper. Investigations were performed in two systems. One of the systems was corresponding to conditions occurring inside the mould cavity immediately after its pouring with liquid metal (Method 1), while the second was simulating conditions deep inside the mould at a certain distance from the casting (Method 2). Investigations were carried out in the CO2 atmosphere and in the air. The water protective coating generated 1.5 to 3 times larger volume of gases than the alcoholic coating (in dependence on the measuring method and atmosphere). The smallest differences occurred in the air atmosphere, while the largest in the CO2 atmosphere.
Mechanical Properties of Plug Welds after Micro-Jet Cooling
Authors: Hadryś D.
Published: January 2017

New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF) in weld metal deposit (WMD) is obtained in MIG welding method with micro-jet cooling in relation to ordinary MIG welding method. This article presents the influence of the cooling medium and the number of micro-jet streams on mechanical properties of the welded joint. Mechanical properties were described by force which is necessary to destroy weld joint.
Use of Specific Properties of Zinc Ferrite in Innovative Technologies
Authors: Kmita A. , Pribulova A. , Holtzer M. , Futas P. , Roczniak A.
Published: January 2017

Zinc ferrite ZnFe2O4 both in the micro and nano scale is widely used in various fields. The article discusses the structure of this compound and its properties in the nanoscale, which is clearly different from those which the ferrite shows in the microscale. The properties of dust generated electric arc furnace, which can contain up to 40% zinc, substantially in the form of ZnFe2O4 are disscused here. Specific properties (electric, magnetic, thermal) of zinc ferrite nanoparticles determine the very wide possibilities of their use, inter alia as catalysts, absorbents, gas sensors, and a tool to combat cancer.
The Use of Instrumental Hardness Measurements in Determining Stresses in the Elastic Elements of a Manipulator for Servicing Water and Sewage Networks
Authors: Kaczyński R. , Rogowski G. , Hościło B.
Published: January 2017

The paper presents the design of a manipulator for servicing the elements of water and sewage infrastructure, in particular for installation and dismantling of pressure transducers without the need for earthmoving. To build this device the resilient elements, cold shaped, responsible for centering the manipulator in the technical tube were used. In their construction a method was applied of estimating the value of residual stresses in the cold shaped material, based on measurements of instrumental hardness. The experimental verification of numerical simulation of instrumental hardness measurements of flat springs made of 1.1274 steel is described.
Microstructural and Equilibrium Adsorption Study of the System of Waste Foundry Molding Sand/Cu (II) Ions
Authors: Strkalj A. , Glavas Z. , Slokar L.
Published: January 2017

This paper deals with the waste foundry molding sand which originally comes from the casting production. Adsorption of Cu (II) ions on the waste foundry molding sand was studied. Experimental data were processed using adsorption isotherms. Obtained results show that the experimental data are best described by the Langmuir isotherm. The following adsorption capacities are obtained: 7.153 mg/g to 293 K, 8.403 mg/g at 333 K and 9.208 mg/g at 343 K. The kinetics and thermodynamics of the process were analysed. The obtained results indicate that the adsorption process takes place according to the pseudo second order kinetic model with the following constants: 0.438 g/mg min at 293 K, 0.550 g/mg min at 333 K and 1.872 g/mg min at 343 K. The following values of ΔG° were obtained: − 95.49 J/mol at 293 K, − 736.99 J/mol at 333 K and − 1183.46 J/mol at 343 K. The value of ΔH° is − 4.16 kJ/mol and the value of ΔS° is 15.17 J/molK. These results were confirmed by microscopic examinations. The results indicate that the adsorption process of Cu (II) ions on waste foundry molding sand is possible. Results of microscopic examinations show the homogeneity of the surface, which is proof of the chemisorption. Cu (II) ions on the surface of the waste foundry molding sand were detected after adsorption by EDS analysis, which proves the existence of the adsorption process.
Stress and Strain Analysis and Microstructure of Al/Cu Clad Composite Fabricated by Cold Extrusion
Authors: Junting Luo , Yahong Xue , Yongkang Liu , Jianyong Li , Shuangjing Zhao
Published: January 2017

A five-zone describing model for extrusion of aluminum/copper clad composite was established. Stress and strain were also analyzed by finite element method. The distribution rules of grain size were researched by critical shear strain theory, and zoning phenomenon of grain size was discovered. The grain size of deformed aluminum material becomes gradually finer from center to the interface. The grain size is much fine and the critical shear strain reaches the maximum value in the interface. The grain size of copper material reduces gradually from center to both the interface and exterior surface, which is caused by the higher value of critical shear strain in the interface and exterior surface. The analysis results were verified by microstructure observation and mechanical properties test, indicating that the distribution of grain size for cold extrusion forming can be interpreted by critical shear strain theory.
On the Load Dependence of Micro-Hardness Measurements: Analysis of Data by Different Models and Evaluation of Measurement Errors
Authors: Petrík J.
Published: January 2017

The influence of applied loads between 0.09807 N and 0.9807 N on measured values of micro-hardness was evaluated by Meyer’s index n, proportional specimen resistance model (PSR) and Hays – Kendall methods, Total Dispersion Zone and Analysis of Variance (ANOVA). The measurement was repeated 6 times using the same hardness reference block with standard hardness Hc= 327 HV0.05 as a sample. The influence of the load on the measured value of micro-hardness is statistically significant, and the relationship between applied load and micro-hardness manifests reverse indentation size effect (ISE) for most of “measurements”. The high value of the uncertainty of results can affect the existence and nature of ISE, especially at low loads.
Mechanical Properties and Corrosion Resistance of HVOF Sprayed Coatings Using Nanostructured Carbide Powders
Authors: Żórawski W. , Makrenek M. , Góral A.
Published: January 2017

Nanostructured and composite WC-12Co coatings were prepared by means of the supersonic spray process (HVOF). The microstructure and composition of WC-12Co nanostructured powder were analyzed by scanning electron microscope (SEM) and transmission electron microscope (TEM). Investigations revealed nano grains of WC with the size in the range of 50-500 nm. The nanostructured sprayed coating was analysed by SEM and phase composition was investigated by X-ray diffractometer (XRD). A denser coating structure with higher hardness was observed compared to conventional coating with a small amount of W2C, WC1−x, W and some amorphous phase. Young’s modulus and hardness were determined by depth sensing indentation in HVOF sprayed WC-12Co nanostructured coatings. Results were compared to conventional coatings and the relevance of the nanostructure was analyzed. An indentation size effect was observed on the polished surface and cross-section of both coatings. Data provided by indentation tests at maximum load allow to estimate hardness and elastic modulus. Enhanced nanomechanical properties of conventional coating in comparison to nanostructured one were observed. Nanostructured coatings WC-12Co (N) revealed significantly better corrosion resistance.
Nanocrystalline Ag-Re Composite as a Potential Material for Electric Contacts Fabrication
Authors: Kołacz D. , Księżarek S. , Woch M. , Karwan-Baczewska J. , Staszewski M. , Rudnicki K. , Borkowski P. , Sienicki A.
Published: January 2017

A new silver-based composite material with an addition of 1 and 10 mass % of rhenium, for prospective application in the production of electric contacts, has been presented. The paper shows results of the research and experimental works aimed at developing technology for fabrication of semiproducts (wires and bimetallic contacts) by classical powder metallurgy methods and by a method enabling production of nanocrystalline composite. At each stage of the processes involved, physical, mechanical and technological properties of the materials were investigated. Particular attention was given to final products and semiproducts prepared in a form of bimetallic contacts. It was found that the composite with nanocrystalline structure may be a good material for ecological electric contacts.
Investigations of Plasticity of Hard-Deformed Aluminium Alloys of 5xxx Series Using Torsion Plastometer
Authors: Laber K. , Kawałek A. , Sawicki S. , Dyja H. , Borowski J. , Leśniak D. , Jurczak H.
Published: January 2017

This paper presents the results of the study aimed at determination of plasticity of selected grades of hard-deformed aluminium alloys of 5xxx series in terms of parameters characteristic for the process of extrusion. The examinations were carried out for 5083 and 5754 alloys in the torsion test using STD 812 torsion plastometer. Using the empirical tests, the study evaluated yield stress of alloys depending on strain, strain rate and temperature and the results were approximated and mathematical models of rheological properties of the aluminium grades studied were determined within the range of parameters of deformation and temperature.
Analysis of the State of Stress in Cathode Block of an Aluminium Electrolytic Cell During Formation of Connection with the Steel Pin by Cast Iron Pouring
Authors: Piekło J. , Maj M.
Published: January 2017

The article presents various aspects of the analysis of the state of stress in carbon block induced by the effect of temperature when a steel pin is connected to the block by pouring a shaped groove with cast iron. Changes in the temperature and state of stress in the block were examined by FEM (Abaqus program). The numerical model was validated by experimental measurements of pin deflection during pouring of the groove with cast iron.
New Al-Ag Alloys for Electrical Conductors with Increased Current Carrying Capacity
Authors: Mamala A. , Knych T. , Kwaśniewski P. , Kawecki A. , Kiesiewicz G. , Sieja-Smaga E. , Ściężor W. , Gniełczyk M. , Kowal R.
Published: January 2017

The paper shows a new idea of aluminium alloys. New alloys with specially selected alloying element i.e. silver have electrical conductivity similar to pure aluminium at ambient temperature and better than pure aluminium electrical conductivity at increased temperatures. Al-Ag alloys for electrical applications (mainly for electrical conductors) due to high electrical conductivity at increased temperatures at the level of the maximum conductor working temperatures give possibility of better current capacity of conductors.

The experimental results of basic mechanical properties and the electric conductivity versus temperature relation are shown in the paper as well as examples of the tested material operational properties.

The summary gives theoretical analysis based on examples of the potential applications of Al-Ag alloys (new conductor designs) which provide the benefits of the new solutions in comparison to traditional conductors.
Tribological Examination of Different Steel Materials after Special Heat Treatment and Salt Bath Nitriding
Authors: Opaliński M. , Mazuro P. , Klasik A. , Rostek E.
Published: January 2017

The main aim of the presented research was examination of new tribological pairs made of different types of steel. Materials of disc probes were submitted to unusual heat treatment processes and salt bath nitriding. The research is focused on the friction coefficients and mass losses of the material probes. Based on the results it was noticed that the best wear resistant pair was bearing steel 100Cr6 coupled with high speed steel S705. The lowest friction coefficient appeared for the pair bearing steel 100Cr6 and maraging steel C350.
Rheology of StelliteTM 21 Alloy in Semi-Solid State
Authors: Sołek K. , Kapranos P.
Published: January 2017

The main objective of this study was to conduct an analysis of the rheological properties of StelliteTM 21 alloy in the semi-solid state, as the results could be used for identifying the appropriate temperature range for thixoforming of this alloy, and a secondary objective of the experimental work was the development of mathematical model of the alloy’s apparent viscosity. Such viscosity models are necessary for numerical simulations of the thixoforming processes. The StelliteTM 21 alloy exhibits high hardness and thus shaping in the semi-solid state is promising route of production of parts from this alloy. Within the confines of experimental work the measurement methods of the rheological properties at high temperatures was developed. They are based on the use of specially designed viscometer equipped with high temperature furnace.
Fractography of Sinteraustempered and Sinterhardened Fe-3Mn-0.8C PM Steels
Authors: Tenerowicz M. , Sułowski M.
Published: January 2017

Sintered steels with the addition of manganese are widely used in industry because of their attractive mechanical properties. The main problem of using manganese in powder metallurgy steel production is its high affinity for oxygen. The choice of proper sintering parameters can significantly improve the properties of the final product.

For the present investigations Höganäs iron powder grade NC 100.24, low-carbon (1.3%C) ferromanganese Elkem (Eramet Norway Sauda – formerly Elkem Manganese Sauda) and graphite powder grade C-UF were used as the starting powders. Mixture of powders, containing 3% Mn and 0.8% C, was prepared in Turbula mixer for 30 minutes. Following mixing, “dog bone” compacts were pressed at 660 MPa according to PN-EN ISO 2740 standard. Sintering of compacts was carried out in the laboratory tube furnace at 1120 and 1250°C for 60 minutes in air or pure nitrogen (99.999%N2). The present investigation deals with the comparison of two heat treatment routes: sinterhardening (SH) and sinteraustempering (SAT), carried out both in air and pure nitrogen. Mechanically tested steels were investigated using JEOL JSM 700F completed with EDS. Metallography tests were carried out on 3% Nital etched samples.

In this paper the results of mechanical tests and metallography and fractography investigations are shown. According to the results obtained, it can be assumed that for sinteraustempering higher temperature does not influence mechanical properties of sintered steels. For both methods using pure nitrogen as sintering atmosphere gave better results.
Microstructure and Corrosion Resistance of Aluminium and Copper Composite Coatings Deposited by LPCS Method
Authors: Winnicki M. , Rutkowska-Gorczyca M. , Małachowska A. , Piwowarczyk T. , Ambroziak A.
Published: January 2017

The paper presents the study of microstructure and corrosion resistance of composite coatings (Al+Al2O3 and Cu+Al2O3) deposited by Low Pressure Cold Spraying method (LPCS). The atmospheric corrosion resistance was examined by subjecting the samples to cyclic salt spray and Kesternich test chambers, with NaCl and SO2 atmospheres, respectively. The selected tests allowed reflecting the actual working conditions of the coatings. The analysis showed very satisfactory results for copper coatings. After eighteen cycles, with a total time of 432 hours, the samples show little signs of corrosion. Due to their greater susceptibility to chloride ions, aluminium coatings have significant corrosion losses.
Reduced Glass-Transition Temperature versus Glass-Forming Ability in FeCoB-Based Amorphous Alloys
Authors: Nabiałek M.
Published: January 2017

This work presents studies concerning the relationship between reduction of glass transition temperatureTrgand the glass-forming ability of FeCoB-based alloys. On the basis of theoretical considerations, Turnbull [1] determined the reduced glass transition temperature (Tg/Tl) as being 2/3 of the Vogel–Fulcher–Tammann (VFT) temperature; since then, continuous research has been carried out, aiming to calculate the Trg parameter and describe its relationship with glass-forming ability. In the majority of research papers, the reduced glass transition temperature is calculated from the relationshipTg/Tm, proposed by Uhlmann and Davies [2, 3]. On the basis of differential scanning calorimetry (DSC) studies, undertaken in this current work, the values of the following temperatures have been found:Tg,Tx, Tmand Tl, in addition to the temperature ranges:ΔTx,ΔTmandΔTl. The correlation between:Tg/Tm,Tg/Tland the glass-forming ability also has been discussed. Finally, for the investigated alloys, it has been found that the relationship proposed by Turnbull is reliable over a wide range ofΔTm.
The Analysis of “Hot” Drawing Process of Trip Steel Wires at Different Initial Temperatures
Authors: Wiewiórowska S. , Muskalski Z. , Siemiński M.
Published: January 2017

In the work the results of preliminary research of the „hot” drawing process of TRIP steel wires at different initial temperatures has been shown.

The study is expected to find whether the „hot” drawing process, and so the increase in the temperature of the material being drawn, will block the transformation of retained austenite into martensite and, as a consequence, influence the properties of drawn wire.
Supporting the Manufacturing Process of Metal Products with the Methods of Artificial Intelligence
Authors: Wilk-Kołodziejczyk D.
Published: January 2017

The aim of this research programme was to develop a series of methods and solutions to support the decision-making process in foundry and materials engineering. The specific problems discussed included the selection of methods for data processing and knowledge representation formalisms, backed up by the creation of decision algorithms based on contemporary achievements of artificial intelligence, tailored to the needs of foundry industry and metallurgy. The manufacturing process of metal items is associated with many aspects, which affect the quality of end product. For process engineers responsible for the supervising and planning of production, an important feature is, among others, the diversified nature of numerous aspects of the knowledge acquisition and integration from distributed sources of information which, when made available in an appropriate manner, can support the improvement of manufacturing process.
Modified Twin-Spot Laser Welding of Complex Phase Steel
Authors: Różański M. , Morawiec M. , Grajcar A. , Stano S.
Published: January 2017

The work addresses modified methods of twin-spot laser welding of complex phase steel sheets and investigates the effects of laser beam distribution on the macrostructure, microstructure and hardness. The research-related results were obtained for the beam power distributions of 50%-50%, 60%-40% and 70%-30%. Test joints were made using a Yb:YAG disc laser with a maximum power of 12 kW and a welding head by means of which it was possible to focus a laser beam on two spots. It was found that the change in the laser beam distribution affects geometrical features of the joint. The application of the second beam of lower power enables obtaining tempering-like effects, which finally lead to the beneficial hardness reduction both in the fusion zone and in heat-affected zone. The identification of various microstructural constituents in different zones of the joint was performed using light microscopic micrographs and scanning electron images.
Acetylene Flow Rate as a Crucial Parameter of Vacuum Carburizing Process of Modern Tool Steels
Authors: Rokicki P. , Dychton K.
Published: January 2017

Carburizing is one of the most popular and wide used thermo-chemical treatment methods of surface modification of tool steels. It is a process based on carbon diffusive enrichment of the surface material and is applied for elements that are supposed to present higher hardness and wear resistance sustaining core ductility. Typical elements submitted to carburizing process are gears, shafts, pins and bearing elements. In the last years, more and more popular, especially in highly advanced treatment procedures used in the aerospace industry is vacuum carburizing. It is a process based on chemical treatment of the surface in lower pressure, providing much higher uniformity of carburized layer, lower process cost and much lesser negative impact on environment to compare with conventional carburizing methods, as for example gas carburizing in Endo atmosphere. Unfortunately, aerospace industry requires much more detailed description of the phenomena linked to this process method and the literature background shows lack of tests that could confirm fulfilment of all needed requirements and to understand the process itself in much deeper meaning. In the presented paper, authors focused their research on acetylene flow impact on carburized layer characteristic. This is one of the most crucial parameters concerning homogeneity and uniformity of carburized layer properties. That is why, specific process methodology have been planned based on different acetylene flow values, and the surface layer of the steel gears have been investigated in meaning to impact on any possible change in potential properties of the final product.
Interaction of Liquid Steel with Mould Flux in Continuous Casting Bloom Mould - Numerical Simulations and Industrial Experiences
Authors: Cwudziński A. , Jowsa J. , Przegrałek P.
Published: January 2017

The device under examination is a mould of a capacity of 0.5 Mg and with inner cross-section of 280×400 mm. The virtual model of the facility under investigation was made using Gambit, DesignModeler and Meshing programs. Computer simulation of the liquid steel flow and mould flux behaviour in turbulent motion conditions was done using the Ansys-Fluent® computer program. On the basis of earlier researches the volume of fluid (VOF) model was applied. Based on computer simulations carried out, steel flow and flux behaviour fields and curves of flux mould entrainment concentration were obtained. The results obtained from numerical simulation were compared with the data obtained during bloom casting under industrial conditions. Based on the obtained information on the interaction of steel with mould flux, the region was determined, in which conditions likely to favour the entrainment of slag portions into the forming bloom exist.
Physical and Numerical Investigations of Mould Flux Entrainment into Liquid Steel
Authors: Jowsa J. , Bielnicki M. , Cwudziński A.
Published: January 2017

This paper presents results of model tests, performed in order to analyze phenomenon of slag droplets entrainment into steel in mould, during continuous casting process. The carried out studies took the form of laboratory experiments using physical model, in which – using similarity criteria – the behaviour of interfacial boundary liquid steel-liquid slag has been simulated using water and silicon oils, differing in physicochemical properties. Additionally, based on PIV (Particle Image Velocimetry) measurements and numerical simulations, vector flow field and values of critical velocities, at which observed the occurrence of interfacial boundary silicon oil-water instability have been identified. Based on the carried out investigations, results, that illustrate relationship between critical entrainment velocity and physicochemical properties of oils have been presented.
Optimization of Steel Flow in the Tundish by Modifying its Working Area
Authors: Warzecha P. , Hutny A. M. , Warzecha M. , Merder T.
Published: January 2017

Presented paper describes model investigations carried out on six-strand continuous casting tundish. Numerical analysis is based on simulations performed with the use of commercial code ANSYS Fluent. The analysis concerns determination of hydrodynamic conditions of the flow in the analysed tundish, with nominal capacity of 22 Mg, and its optimisation by modification of the flow structure in the tundish working area. Four different flow control devices (FCD) were proposed.

Results of investigations presented in the paper include the distribution of velocity vectors and distribution of temperature and turbulence kinetic energy. Additionally, for more detailed comparative analysis, the macroscopic characteristics of residence time distribution (RTD) in the reactor, and the transition zone ranges were determined for each of the variants.
The Effect of Thermophysical Parameters on Temperature Distribution in the Primary Cooling Zone
Authors: Miłkowska-Piszczek K.
Published: January 2017

The values of thermophysical properties obtained from the experimental research, and those that were calculated with thermodynamic databases, are crucial parameters which were used in the numerical modelling of the steel solidification process. This paper presents the results of research on the impact of specific heat and enthalpy, along with the method of their implementation, on temperature distribution in the primary cooling zone in the continuous steel casting process. A cast slab – with dimensions of 1100 mm and 220 mm and a S235 steel grade – was analysed. A mould with a submerged entry nozzle (SEN), based on the actual dimensions of the slab continuous casting machine, was implemented. The research problem was solved with the finite element method using the ProCAST software package. Simulations were conducted using the “THERMAL + FLOW” module.
Optimization of Chemical Composition of the Mould Powder for Casting Ø 170 mm Billets from C45 Steel
Authors: Kania H. , Nowacki K.
Published: January 2017

Physico-chemical properties of mould powders and assumed casting parameters for the particular steel grade influence the way of lubricating the surface of the skin of concast billets formed in the mould, as well as heat transfer along its circumference.

The paper presents research which main aim was to improve the surface quality of continuous casting round billets (Ø 170 mm) cast from C45 steel. Improvement of the surface quality can be obtained by designing the chemical composition of mould powder for local casting conditions and the technical and technological parameters of CC equipment. Based on the experimental casting from C45 medium carbon steel it was found that there are relationships between the physicochemical properties of mould powder and intensity of skin lubrication and heat transmission to the mould wall.
Analysis of Agglomeration of Al2O3 Particles in Liquid Steel
Authors: Kalisz D. , Żak P.L. , Kuglin K.
Published: January 2017

The removal of non-metallic inclusions from liquid steel is a result of co-operation of fluctuation, adhesion and agglomeration effects, with emphasis on agglomeration which plays the most important role. It is based on a few types of collisions between non-metallic particles, where turbulent collisions are most prominent. As a result of agglomeration, nonmetallic inclusions are intensely removed through flotation and increase of different dimensions of inclusions, which manifests itself with the occurrence of clusters mainly composed of Al2O3precipitations. Authors investigated the agglomeration effect by making computer simulations with the use of the PSG method. The calculations were performed for a definite population of spherical particles of radiusrin the steel volume. The applied calculation method allows for analyzing the dynamics of the collision process. The assumed initial number of particles remains constant, only the number of particles in specific size-groups varies. It was also revealed that the process of agglomerates formation is much faster for particles having a bigger initial radius. In the case of very small precipitations (r=1 μm) their removal through agglomeration is very difficult because the probability those collisions can take place between them rapidly decreases.
Hypoeutectic Silumin to Pressure Die Casting with Vanadium and Tungsten
Authors: Szymczak T. , Gumienny G. , Pacyniak T.
Published: January 2017

The basic aim of this study is to investigate the effect of vanadium and tungsten on the crystallization process, microstructure and mechanical properties of silumin grade EN-AC 46000. The research involved a derivative thermal analysis DTA of the crystallization process, the metallographic analysis as well as the mechanical properties. The metallographic analysis was carried out on pressure die castings and made in the DTA probe. Vanadium and tungsten were added simultaneously to silumin in amount of approximately 0.1; 0.2; 0.3 and 0.4%. The DTA studies have shown the similar shape of all crystallization curves. It has been shown the additives of vanadium and tungsten in pressure die cast silumin can significantly increase its tensile strength as an well as elongation.
Austempered Ductile Iron Manufacturing Data Acquisition Process with the Use of Semantic Techniques
Authors: Wilk-Kołodziejczyk D. , Kluska-Nawarecka A.S. , Regulski K. , Adrian W. , Jaśkowiec K.
Published: January 2017

The aim of this work was to propose a methodology supporting the task of collecting the comparative data on studies of the mechanical properties of ADI. Collecting of research data is an important step in the process of finding the optimum design solutions for newly made products - experimental data allow us properly calibrate the manufacturing process of ADI to let the final product achieve the required properties. Parameters of the ADI production process, i.e. the time and temperature of austenitising and austempering, as well as the alloying elements added to ductile iron affect the ADI properties. The design process can use research data collected, among others, from the Web. As stated in the article, the process of data acquisition can be supported by semantic technologies, including ontologies which are descriptive logic formalism.
Statistical Assessment of the Impact of Elevated Contents of Cu and Ni on the Properties of Austempered Ductile Iron
Authors: Nawrocki P. , Kochański A. , Myszka D.
Published: January 2017

The article presents a statistical analysis of data collected from the observation of the production of austempered ductile iron. The impact assessment of the chemical composition, i.e. high contents of Cu and Ni on the properties of ductile iron isothermal tempered is critical to find the right chemical composition of austempered ductile iron. Based on the analyses range of the percentage of Cu and Ni which were selected in the cast iron to obtain material with high strength properties.