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Search Results: 1 - 10 of 1659 matches for " Maciej Pytel "
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Scavenging Properties of the Polyamine Functionalized Gels Based on the Glycidyl Methacrylate Terpolymers  [PDF]
Agnieszka Bukowska, Wiktor Bukowski, Maciej Pytel
Open Journal of Polymer Chemistry (OJPChem) , 2015, DOI: 10.4236/ojpchem.2015.54008
Abstract: Scavenging abilities of the ethylenediamine, diethylenetriamine and tris(2-aminoethyl)amine functionalized resins derived from the low cross-linked glycidyl methacrylate-styrene gels in relation to the selected transition metal ions and organic (acid chlorides) electrophiles were explored. The synergetic effects of the solvents were found for the metal ion uptake. In this case a pair of solvents capable simultaneously to swell the hydrophobic core of the resins and interact with the polar amine groups turned out to be a more effective medium for activation of the nucleophilic functionalities of the resins. The resin with ethylenediamine moieties proved to be effective in scavenging acyl chlorides from methylene chloride as well. However, it did not provide complete removing sulphonyl chlorides from the solutions. These organic electrophiles were removed effectively by the resins bearing tris(2-aminoethyl)amine functionalities.
Kinetics Growth and Oxidation Resistance of Aluminide Coatings Deposited by the CVD Method on Re 80 Superalloy  [PDF]
Marek Goral, Maciej Pytel, Kamil Dychton, Andrzej Nowotnik
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2012, DOI: 10.4236/jmmce.2012.118078
Abstract: The preliminary results of research on forming the aluminide coatings using CVD method were presented in the article. The coatings were obtained in low activity process on the surface of Rene 80 superalloy. The microstructure analysis and chemical composition analysis were performed applying different values of aluminizing process parameters. The authors present in the article the results of oxidation resistance analysis of aluminide coatings which were obtained on the surface of Rene 80 superalloy using various techniques. It was shown that the coating created during the CVD process was characterized by a good oxidation resistance at the temperature of 1100℃.
Charakterystyka tworzyw ceramicznych otrzymanych z udzia em zu ytych mas odlewniczych ze spoiwem organicznym
Z. Pytel
Archives of Foundry Engineering , 2012,
Abstract: Referat zawiera wyniki badań tworzyw ceramicznych otrzymanych z mas plastycznych, w których sk adnikiem przeznaczonym doschudzania surowca ilastego by y zu yte masy odlewnicze. Wprawdzie masy te pochodzi y z ró nych odlewni, to jednak wspóln ichcech by rodzaj spoiwa wykorzystywanego do ich przygotowania. Spoiwa te nale a y do grupy spoiw organicznych, opartych na ywicach furanowych lub fenolowo-formaldehydowych. Ze wzgl du na potencjaln mo liwo emisji do atmosfery szkodliwychsubstancji gazowych w postaci wielopier cieniowych w glowodorów aromatycznych (WWA), mog cych si uwalnia w warunkachwysokich temperatur charakterystycznych dla procesu wypalania wyrobów ceramicznych, podj te badania stanowi prób utylizacjijednego z najbardziej niebezpiecznych rodzajów zu ytych mas odlewniczych.Koncepcja badań przewiduje otrzymanie zasadniczo dwóch rodzajów tworzyw ceramicznych. Pierwszy rodzaj stanowi tworzyworeferencyjne otrzymane z masy ceramicznej, w której rol dodatku schudzaj cego surowiec ilasty spe nia tradycyjny dodatek w postacipiasku kwarcowego pochodzenia naturalnego. Drugi rodzaj stanowi tworzywa eksperymentalne otrzymywane równie z masceramicznych, lecz w tym przypadku dodatkiem schudzaj cym by materia krzemionkowy otrzymany w wyniku odpowiedniegoprzetworzenia zu ytych mas odlewniczych zawieraj cych pozosta o ci spoiw organicznych, wprowadzany w ekwiwalentnej ilo ciw stosunku do piasku kwarcowego. Ocen przydatno ci tego rodzaju surowca wtórnego we wspomnianym kierunku utylizacji,przeprowadzono w oparciu o wynik analizy porównawczej obu rodzajów tworzyw, obejmuj cej swym zakresem ich podstawowe cechyu ytkowe oraz wybrane elementy mikrostruktury. Uzyskane wyniki badań wiadcz o braku negatywnego oddzia ywania na rodowiskonaturalne zwi zane z potencjaln mo liwo ci emisji WWA w trakcie produkcji tworzyw ceramicznych z udzia em zu ytych masodlewniczych zawieraj cych pozosta o ci spoiw organicznych, jak równie potwierdzaj mo liwo otrzymywania z ich udzia emtworzyw ceramicznych odznaczaj cych si porównywalnymi w a ciwo ciami w stosunku do tworzyw referencyjnych.
The properties of sand-lime bricks manufactured with the use of waste moulding and core sands
Z. Pytel
Archives of Foundry Engineering , 2010,
Abstract: The paper summarises the laboratory research data on potential applications of selected mould and core mix wastes and dusts fromregeneration processes as alternative or supplementary materials to be added to natural silica sands used in manufacturing of sand-limebricks. The rational behind this solution is the large silica content in used moulding and core mix, their matrices being high-quality natural silica sands. The research program shall involve obtaining the series of silicate sample products, press-formed and made from mixtures containing the waste materials discussed here. In the course of laboratory tests autoclaved materials shall be manufactured, including sand-lime bricks. Apart from conventional components: natural silica sand and quicklime, the prepared mixture shall contain pre-processed mould and core mix and dusts from regeneration processes, depending on the type of applied binder. The previously mentioned wastes from the foundry processes were introduced to the basic composition mix as substitutes for silica sand, ranging from 0-100 % (by weight). Potential applications of these wastes were explored using the comparative analysis, covering the basic functional parameters of two types of materials: the reference material made from conventional constituents and several experimental formulas containing additives, differing in qualitative and quantitative composition. Characteristics of thus obtained materials are supported by selected SEM+EDS test results.
Quantum Cryptography - The Issue of Security in Selected Quantum Protocols and the Issue of Data Credibility
Magdalena Krzyszkowska-Pytel
Theoretical and Applied Informatics , 2010, DOI: 10.2478/v10179-010-0020-2
Abstract: Quantum cryptography, a field of science that had not been known before, developed rapidly in the late 20th century. It originated from a combination of quantum mechanics and information technology. The present paper presents the possibilities of using quantum mechanics in cryptography and considers whether there are any practical solutions to the important class of problems regarding the security of transmitted information.
Identification of temperature changes dynamics in selected castings as a contribution to performance life improvement
A. Pytel,S. Pysz
Archives of Foundry Engineering , 2010,
Abstract: Parameters describing boundary conditions and dynamics of temperature changes during casting cooling in foundry moulds and thesuccessive performance, especially as regards the massive cast elements, were discussed. Considering the specific nature of castingoperation, non-standard methods of examination of the isotherms of temperature fields on the casting surface were described to determinelocal overheating resulting from the technological process, chemical composition, properties of the currently applied insulation materials,casting defects and/or design. Identification of these parameters can be interpolated to laboratory conditions and to the validation of virtual models subject to computer simulation. The use in simulation of genetic algorithms combined with the results of measurements under real conditions enables more precise determination of the performance parameters, including critical states of stresses present in a structure. This should allow further optimisation of the massive castings design, considering the specific nature of a manufacturing process (alloy composition included), combined with performance parameters. Measures described here are expected to contribute to the reduced casting weight and longer time of operation.
Recycling process of casting molds applying to precision castings
M. Drajewicz,M. Pytel
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: The present work relates to investigations about the possibility of recycling and producing sinters from ceramic molds. These molds are applied for producing precise single crystal casts of nickel based superalloys to elements witch are applied to the hot section of aircraft jet engines.Design/methodology/approach: The processes of milling were carried out using the vibratory mill Herzog HSM 100H and the planetary grinder Pulverisette 7 - Fritsch Company. The measurements of all kinds of powders were conducted by using of the Kamika IPS U Analyzer and Malvern Nanosizer-ZS. To the purpose of analysis of the chemical composition an X-ray microanalysis technique was applied with the dispersion of the energy (EDS) using of Thermo and Noran equipment. Findings: On the basis of examinations carried out on the powders before and after processes of milling and after processes of pressing and sintering of powders, it is possible to state that technological processes of reuse and further applying of used molds are possible. Processes of pressing were conducted applying different amounts of powders. Powders were pressed both without the addition as well as with the addition of modifiers which were added to basic powder in appropriate amounts. It was found that processes of pressing and sintering in both cases showed good results. Surfaces of pressed and sintered tablets were smooth and not-delaminated as well as did not shell.Research limitations/implications: Results will be used for future researches among others concerning the research on mechanical and thermal properties.Practical implications: Waste products and their reuse, recycling and especially consolidation of dangerous and hazardous compounds including of ceramic materials from foundry industry, will have an important place in the future on account of problems with their recycling and the storage.Originality/value: Researches on new possibilities of the application and properties of waste materials.
Stability of Frustration-Free Hamiltonians
Spyridon Michalakis,Justyna Pytel
Physics , 2011, DOI: 10.1007/s00220-013-1762-6
Abstract: We prove stability of the spectral gap for gapped, frustration-free Hamiltonians under general, quasi-local perturbations. We present a necessary and sufficient condition for stability, which we call "Local Topological Quantum Order" and show that this condition implies an area law for the entanglement entropy of the groundstate subspace. This result extends previous work by Bravyi et al., on the stability of topological quantum order for Hamiltonians composed of commuting projections with a common zero-energy subspace. We conclude with a list of open problems relevant to spectral gaps and topological quantum order.
Constructing optimal entanglement witnesses. II
Dariusz Chruscinski,Justyna Pytel
Physics , 2010, DOI: 10.1103/PhysRevA.82.052310
Abstract: We provide a class of optimal nondecomposable entanglement witnesses for 4N x 4N composite quantum systems or, equivalently, a new construction of nondecomposable positive maps in the algebra of 4N x 4N complex matrices. This construction provides natural generalization of the Robertson map. It is shown that their structural physical approximations give rise to entanglement breaking channels.
Artificial Neural Network as a FPGA Trigger for a Detection of Very Inclined Air Showers
Zbigniew Szadkowski,K. Pytel
Physics , 2014,
Abstract: Neutrinos can interact in the atmosphere (downward-going {\nu}) or in the Earth crust (Earth-skimming {\nu}), producing air showers that can be observed with arrays of detectors at the ground. The surface detector array of the Pierre Auger Observatory can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). Up to now, the Pierre Auger Observatory did not find any candidate for a neutrino event. A very low rate of events potentially generated by neutrinos is a significant challenge for a detection technique and requires both sophisticated algorithms and high-resolution hardware. We present a trigger based on a pipeline artificial neural network (ANN) implemented in a large FPGA which after learning can recognize traces corresponding to special types of events. The structure of an ANN algorithm being developed on the MATLAB platform has been implemented into the fast logic of the biggest Cyclone V E FPGA used for the prototype of the Front-End Board for the Auger-Beyond-2015 effort. Several algorithms were tested, however, the Levenberg-Marquardt one seems to be the most efficient. The network was taught: a) to recognize "old" showers (learning on a basis of real very inclined Auger showers (positive markers) and real standard showers especially triggered by Time over Threshold (negative marker), b) to recognize "young" showers (on the basis of simulated "young" events (positive markers) and standard Auger events as a negative reference). A three-layer neural network being taught by real very inclined Auger showers shows a good efficiency in pattern recognition of 16-point traces with profiles characteristic of "old" showers.
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