bluuebunny/crossref_metadata_2025_split huggingface dataset:
On parameters determination of multi-port equivalent scheme for multi-winding traction transformers
Authors: Sobczyk Tadeusz J. , El Hayek Joseph 
Published: May 2015

Abstract
This paper aims to present a new equivalent scheme of multi-windings traction transformers, based on multiport purely inductive circuit. The mathematical background of this equivalent scheme is described. The determination of the different scheme elements is made through a finite-elements calculation of both main and leakage inductances, for the case of a four-winding transformer. A procedure is defined, which allows to estimate the values of these elements from some measurements on the transformer at no-load and short-circuit operations. A specific strategy of short-circuit tests is described, allowing to determine all parameters in a rather simple way.
Simulation and experimental results of hybrid electric machine with a novel flux control strategy
Authors: Paplicki Piotr , Wardach Marcin , Bonisławski Michał , Pałka Ryszard 
Published: May 2015

Abstract
The paper presents selected simulation and experimental results of a hybrid ECPMS-machine (Electric Controlled Permanent Magnet Synchronous Machine). This permanent magnets (PMs) excited machine offers an extended magnetic field control capability which makes it suitable for battery electric vehicle (BEV) drives. Rotor, stator and the additional direct current control coil of the machine are analyzed in detail. The control system and strategy, the diagram of power supply system and an equivalent circuit model of the ECPMS-machine are presented. Influence of the additional excitation on the performance parameters of the machine, such as: torque, efficiency, speed limits and back-EMF have also been discussed.
The Effect of Pallet Component Geometry on Temperature Gradient During Cooling
Authors: Bajwoluk A. , Gutowski P. 
Published: May 2015

Abstract
The paper discusses the impact of the geometry of foundry pallet components on the value of temperature gradient on the wall crosssection during heat treatment. The gradient is one of the most important factors determining the distribution of thermal stresses in these items. Analysis of quantitative simulation was carried out to detect possible effect of the type of connection between pallet walls and thickness of these walls (ribs) on the interior temperature distribution during rapid cooling. The analysis was performed for five basic designs of wall connections used in pallets. Basing on the results obtained, the conclusions were drawn on the best connection between the ribs in foundry pallets.
The Mathematical Model of Hydrodynamics and Heat and Mass Transfer at Formation of Steel Ingots and Castings
Authors: Bondarenko V.I. , Bilousov V.V. , Nedopekin F.V. , Shalapko J.I. 
Published: May 2015

Abstract
The generic mathematical model and computational algorithm considering hydrodynamics, heat and mass transfer processes during casting and forming steel ingots and castings are offered. Usage domains for turbulent, convective and non-convective models are determined depending on ingot geometry and thermal overheating of the poured melt. The expert system is developed, enabling to choose a mathematical model depending on the physical statement of a problem.
Expert System for Analysis of Casting Defects - ESVOD
Authors: Elbel T. , Králová Y. , Hampl J. 
Published: May 2015

Abstract
The powerful tool for defect analysis is an expert system. It is a computer programme based on the knowledge of experts for solving the quality of castings. We present the expert system developed in the VSB-Technical University of Ostrava called ‘ESWOD’. The ESWOD programme consists of three separate modules: identification, diagnosis / causes and prevention / remedy. The identification of casting defects in the actual form of the system is based on their visual aspect.
The Reliability of the Results of the Modified Low-cycle Fatigue Test for Cast Iron Evaluated by Metallographic Studies
Authors: Maj M. , Pietrzak K. 
Published: May 2015

Abstract
This study discloses the characteristic features of the modified low-cycle fatigue test used for the determination of the mechanical properties of two types of cast iron, i.e. EN-GJL-250 and EN-GJS-600-3. For selected materials, metallographic studies were also conducted in the range of light microscopy and scanning microscopy.
Prediction of Secondary Dendrite Arm Spacing in Squeeze Casting Using Fuzzy Logic Based Approaches
Authors: Patel M.G.C. , Krishna P. , Parappagoudar M.B. 
Published: May 2015

Abstract
The quality of the squeeze castings is significantly affected by secondary dendrite arm spacing, which is influenced by squeeze cast input parameters. The relationships of secondary dendrite arm spacing with the input parameters, namely time delay, pressure duration, squeeze pressure, pouring and die temperatures are complex in nature. The present research work focuses on the development of input-output relationships using fuzzy logic approach. In fuzzy logic approach, squeeze cast process variables are expressed as a function of input parameters and secondary dendrite arm spacing is expressed as an output parameter. It is important to note that two fuzzy logic based approaches have been developed for the said problem. The first approach deals with the manually constructed mamdani based fuzzy system and the second approach deals with automatic evolution of the Takagi and Sugeno’s fuzzy system. It is important to note that the performance of the developed models is tested for both linear and non-linear type membership functions. In addition the developed models were compared with the ten test cases which are different from those of training data. The developed fuzzy systems eliminates the need of a number of trials in selection of most influential squeeze cast process parameters. This will reduce time and cost of trial experimentations. The results showed that, all the developed models can be effectively used for making prediction. Further, the present research work will help foundrymen to select parameters in squeeze casting to obtain the desired quality casting without much of time and resource consuming.
Thermal Analysis in the Technological “Step” Test of H282 Nickel Alloy
Authors: Pirowski Z. 
Published: May 2015

Abstract
Superalloys show a good combination of mechanical strength and resistance to surface degradation under the influence of chemically active environments at high temperature. They are characterized by very high heat and creep resistance. Their main application is in gas turbines, chemical industry, and in all those cases where resistance to creep and the aggressive corrosion environment is required. Modern jet engines could never come into use if not for progress in the development of superalloys. Superalloys are based on iron, nickel and cobalt. The most common and the most interesting group includes superalloys based on nickel. They carry loads at temperatures well in excess of the eighty percent of the melting point. This group includes the H282 alloy, whose nominal chemical composition is as follows (wt%): Ni - base, Fe - max. 1.5%, Al - 1.5% Ti - 2.1%, C - 0.06% Co - 10% Cr - 20% Mo - 8.5%. This study shows the results of thermal analysis of the H282 alloy performed on a cast step block with different wall thickness. Using the results of measurements, changes in the temperature of H282 alloy during its solidification were determined, and the relationship dT / dt = f (t) was derived. The results of the measurements taken at different points in the cast step block allowed identifying a number of thermal characteristics of the investigated alloy and linking the size of the dendrites formed in a metal matrix (DAS) with the thermal effect of solidification. It was found that the time of solidification prolonged from less than ome minute at 10 mm wall thickness to over seven minutes at the wall thickness of 44 mm doubled the value of DAS.
Effect of Sr and Sb Modification on the Microstructure and Mechanical Properties of 226 Silumin Pressure Casts
Authors: Szymczak T. , Gumienny G. , Pacyniak T. 
Published: May 2015

Abstract
The work presents the effect of strontium and antimony modification on the microstructure and mechanical properties of 226 silumin casts. The performed research demonstrated that strontium causes high refinement of silicon precipitations in the eutectic present in the microstructure of the examined silumin and it significantly affects the morphology of eutectic silicon from the lamellar to the fibrous one. Sr modification also causes an increase of: the tensile strength „Rm” by 12%; the proof stress „Rp0,2” by 5%; the unit elongation „A” by 36% and the hardness HB by 13%. Antimony did not cause a change in the microstructure of the silumin, yet it caused an increase in Rm and HB by 5%, in Rp0,2 by 7% and in A by 4%.
Analysis of Microstructure Images Referred to Percolation Theory
Authors: Trzaskowski W. , Sobaszek W. , Myszka D. , Świłło S. 
Published: May 2015

Abstract
The paper discusses possible applications of the percolation theory in analysis of the microstructure images of polycrystalline materials. Until now, practical use of this theory in metallographic studies has been an almost unprecedented practice. Observation of structures so intricate with the help of this tool is far from the current field of its application. Due to the complexity of the problem itself, modern computer programmes related with the image processing and analysis have been used. To enable practical implementation of the task previously established, an original software has been created. Based on cluster analysis, it is used for the determination of percolation phenomena in the examined materials. For comparative testing, two two-phase materials composed of phases of the same type (ADI matrix and duplex stainless steel) were chosen. Both materials have an austenitic - ferritic structure. The result of metallographic image analysis using a proprietary PERKOLACJA.EXE computer programme was the determination of the content of individual phases within the examined area and of the number of clusters formed by these phases. The outcome of the study is statistical information, which explains and helps in better understanding of the planar images and real spatial arrangement of the examined material structure. The results obtained are expected to assist future determination of the effect that the internal structure of two-phase materials may have on a relationship between the spatial structure and mechanical properties.
Artificial Neural Network to the Control of the Parameters of the Heat Treatment Process of Casting
Authors: Wróbel J. , Kulawik A. , Bokota A. 
Published: May 2015

Abstract
In the paper the use of the artificial neural network to the control of the work of heat treating equipment for the long axisymmetric steel elements with variable diameters is presented. It is assumed that the velocity of the heat source is modified in the process and is in real time updated according to the current diameter. The measurement of the diameter is performed at a constant distance from the heat source (Δz = 0). The main task of the model is control the assumed values of temperature at constant parameters of the heat source such as radius and power. Therefore the parameter of the process controlled by the artificial neural network is the velocity of the heat source. The input data of the network are the values of temperature and the radius of the heated element. The learning, testing and validation sets were determined by using the equation of steady heat transfer process with a convective term. To verify the possibilities of the presented algorithm, based on the solve of the unsteady heat conduction with finite element method, a numerical simulation is performed. The calculations confirm the effectiveness of use of the presented solution, in order to obtain for example the constant depth of the heat affected zone for the geometrically variable hardened axisymmetric objects
Contribution to the Identification of Porosity Type in AlSiCu High-Pressure-Die-Castings by Experimental and Virtual Way
Authors: Ignaszak Z. , Hajkowski J. 
Published: May 2015

Abstract
The paper concerns the problem of discontinuity in high pressure die castings (HPDC). The compactness of their structure is not perfect, as it is sometimes believed. The discontinuities present in these castings are the porosity as follow: shrinkage and gas (hydrogen and gas-air occlusions) origin. The mixed gas and shrinkage nature of porosity makes it difficult to identify and indicate the dominant source. The selected parameters of metallurgical quality of AlSi9Cu3 alloy before and after refining and the gravity castings samples (as DI - density index method), were tested and evaluated. This alloy was served to cast the test casting by HPDC method. The penetrating testing (PT) and metallographic study of both kinds of castings were realized. The application of the NF&S simulation system allowed virtually to indicate the porosity zones at risk of a particular type in gravity and high-pressure-die-castings. The comparing of these results with the experiment allowed to conclude about NF&S models validation. The validity of hypotheses concerning the mechanisms of formation and development of porosity in HPDC casting were also analyzed.
Wymagania Jakościowe W Procesach Obsług Oraz Napraw Statków Powietrznych
Authors: Woźny Piotr , Błachnio Józef 
Published: May 2015

Abstract
W trakcie eksploatacji statki powietrzne (SP) podlegają użytkowaniu, obsługiwaniu, naprawie i utylizacji. Każdy z tych procesów musi spełnić odpowiednie wymagania jakościowe. W pracy przedstawiono wymagania związane z zarządzaniem jakością, jakie powinien spełniać podsystem obsługi i napraw SP. Przeprowadzono analizę dokumentów zawierających wymagania dotyczące sfery zarządzania, jak i sfery technicznej. Przedstawiono obowiązujące normy i przepisy mające wpływ na zapewnienie jakości procesu naprawy SP. Zawarto opis norm, których przestrzeganie jest niezbędne do skutecznego działania współczesnych podsystemów obsługi i napraw, mających zdecydowany wpływ na utrzymanie wymaganego stanu zdatności SP. Przedstawiono złożoność procesu podejmowania decyzji dotyczących obsług i napraw SP w podsystemie utrzymania zdatności
Quality Requirements Regarding Aircraft Maintenance and Repair Services
Authors: Woźny Piotr , Błachnio Józef 
Published: May 2015

Abstract
During operation, aircraft (AC) are subject to use, maintenance, repair and disposal. Each of those processes requires adequate quality. This study presents requirements related to quality management with which an AC maintenance and repair sub-system ought to comply. Documents containing requirements pertaining to both management and technical aspects have been analysed. Applicable standards and regulations affecting the AC repair process quality assurance have been presented. A description of standards observance of which is required to ensure effective operation of modern AC maintenance and repair subsystems significantly affecting maintenance of the AC required airworthiness has been included. Complexity of the decision-taking process pertaining to AC maintenance and repair within the airworthiness maintenance sub-system has been presented
Investigation Of Tribologic Processes in Bearing Nodes with the Use of the Fam-C And Fdm-A Methods – The Model With Elevated Passive Resistance
Authors: Gębura Andrzej 
Published: May 2015

Abstract
The paper discloses selected results of application of the FAM-C (a.c. generator) and FDM-A (d.c. generator) methods for comprehensive troubleshooting of bearing nodes in single-spool turbojet engines.
A.c. generators provide information about slow-changing processes and, consequently, that information makes it possible to monitor radial and axial clearance of bearings as well as misalignment of shafts. On the other hand, the information transmitted by d.c. generators refers to fast-changing processes and is suitable to monitor dynamic properties of antifriction bearings: variations in the Q factor of bearings, slip factor of mating antifriction surfaces, rates of bearing cage rotation against its journal, etc.
Nearly ten years of observations and data collection from a numerous set of engines during their operation have made it possible to classify processes associated with wear of bearings and categorize them into four phenomenological models. This paper is devoted to the model of elevated passive resistance
Quick Reference Guide for Critical Appraisal of Economics Evaluations for Busy Decision Makers / Kratki referentni vodič za kritičku procenu ekonomskih evaluacija za zauzete donosioce odluka
Authors: Veličković Vladica , Višnjić Aleksandar , Mihajlović Jovan 
Published: May 2015

Summary
Economic evaluations in health economics are analytical methods used for the analysis of costs and consequences of two or more alternative health programs or interventions. These analyses involve identification, measurement, evaluation and comparison of costs and consequences. Whenever there are two alternative health programs or treatments that lead to different consequences and have different cost, it is recommended to use adequate and proven analytical techniques in the process of making a decision on which intervention to choose. Health economics evaluation techniques can be of great benefit as they stand for proven and highly advanced methods that exhibit high degree of usefulness in practice. Validity of results of health economic evaluation and adequacy of their use in practice is doubtless. Nevertheless, it is evident that these results are insufficiently used in everyday decision making practice, even in countries with a very long tradition and developed health economics. This phenomenon is characterized by multifactorial genesis, but its two main causes are reflected in: insufficient training of decision makers in the field of health economics and lack of credibility of studies. With respect to the aforementioned facts, the aim of our paper was to create a tool for decision makers which will enable relatively simple and rapid assessment of relevance and suitability of economics evaluations to their needs.
Turonian (Upper Cretaceous) inoceramid bivalves of the genus Mytiloides from the Sredna Gora Mountains, north-western Bulgaria
Authors: Dochev Docho 
Published: May 2015

Abstract
The inoceramid bivalves of the genus Mytiloides, from the Turonian (Upper Cretaceous) of the Sredna Gora Mts (north-western Bulgaria), are studied. The material comes from three sections: Izvor, Filipovtsi, and Vrabchov dol. Eight species are described taxonomically, with one left in open nomenclature: M. cf. mytiloides (Mantell, 1822), M. mytiloidiformis (Tröger, 1967), M. incertus (Jimbo, 1894), M. scupini (Heinz, 1930), M. herbichi (Atabekian, 1969), M. striatoconcentricus (Gümbel, 1868), M. labiatoidiformis (Tröger, 1967) and M. carpathicus (Simionescu, 1899). Mytiloides incertus and Mytiloides scupini are index species for the eponymous Upper Turonian inoceramid biozones.
Landscape As A Resource For Squat Farming
Authors: TÓTH Attila , FERIANCOVÁ L’ubica 
Published: May 2015

Abstract
The contemporary Urban Agriculture (UA) is represented by a range of diverse farming typologies taking place in the urban environment. Nowadays, there is an unconventional form of UA called squat farming. The research object of this paper is represented by the case study of Can Masdeu which stands for a squatted and cultivated land at the northern city border of Barcelona. The goal of our Short Term Scientific Mission carried out in the Barcelona Metropolitan Region was to define and study diverse typologies of UA at different levels and scales. One of these types is represented by the ongoing phenomenon of squat farming. Concerning this form, there are two main research questions: 1) How are landscape and urban structures influenced and formed by the activity of land cultivation? and 2) How is the social dimension of squat farming structured – who are the users, what is their motivation, aim and vision? To answer the first research question, we applied spatial and perceptual analyses, and concerning the second research question, the users have been interviewed within discussions and questionnaires. The results include characteristics of spatial and social dimensions of squat farming described on the case study of Can Masdeu.
Pollution Spread Analysis In The Malá Nitra River By Using Of 1-D Model
Authors: VELÍSKOVÁ Yvetta , HALAJ Peter , SOKÁČ Marek , BÁREK Viliam 
Published: May 2015

Abstract
The Water Framework Directive (WFD) is a key initiative aimed at improving water quality throughout the EU. The development of the computer technologies enables us to solve the ecological problems in water management practice very efficiently. The mathematical and numerical modelling allows evaluating various situations of contaminants spread in rivers (from everyday wastewater disposal through the fatal discharges of toxic substances) without immediate destructive impact on the environment. The paper deals with 1-dimensional numerical model HEC-RAS and its response on various values of dispersion coefficient. This parameter is one of the most important input data for simulation of pollution spread in streams. There were performed tracer experiments in the Malá Nitra River and results of these measurements are compared with results of numerical simulations. The values of the longitudinal dispersion coefficient were estimated from this comparison. The range of mean values of this coefficient determined on the base of numerical model application was 0.05 – 0.13 m2 s−1, for the other flow condition it was 0.07 – 2.5 m2 s−1 or 0.28 – 0.6 m2 s−1. The next task was carrying out the model sensitivity analysis, which means to evaluate input data influences, especially longitudinal dispersion coefficient, on outputs computed by 1-dimensional simulation model HEC-RAS. According to the results it can be said that the model HEC-RAS responds to longitudinal dispersion coefficient value changes adequately, suitably and proportionately. The application of the model HEC-RAS demonstrated the eligibility for simulation of pollution spread in streams, which means that it is a suitable tool allowing a reasonable support in decision making process connected to river water quality management.
Health protection and risks for rescuers in cases of floods / Zdravstvena zaštita i rizici za spasioce u poplavljenim područjima
Authors: Holcer Janev Nataša , Jeličić Pavle , Grba Bujević Maja , Važanić Damir 
Published: May 2015

Abstract
Floods can pose a number of safety and health hazards for flood-affected populations and rescuers and bring risk of injuries, infections, and diseases due to exposure to pathogenic microorganisms and different biological and chemical contaminants. The risk factors and possible health consequences for the rescuers involved in evacuation and rescuing operations during the May 2014 flood crisis in Croatia are shown, as well as measures for the prevention of injuries and illnesses. In cases of extreme floods, divers play a particularly important role in rescuing and first-response activities. Rescuing in contaminated floodwaters means that the used equipment such as diving suits should be disinfected afterwards. The need for securing the implementation of minimal health and safety measures for involved rescuers is paramount. Data regarding injuries and disease occurrences among rescuers are relatively scarce, indicating the need for medical surveillance systems that would monitor and record all injuries and disease occurrences among rescuers in order to ensure sound epidemiological data. The harmful effects of flooding can be reduced by legislation, improvement of flood forecasting, establishing early warning systems, and appropriate planning and education.