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Search results for: stable isotopes
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Heat Dissipation from the Power Cable in the Casing Pipe
PublicationThe current carrying capacity of a power cable determines its ability to carry a specific current and is related to the efficiency of dissipation of heat generated in the cable laid in a specific environment. The studies were conducted in order to determine how the characteristics of the medium around the cable affected its temperature, and thus the ability of the cable to transmit electricity. The experimentation in the lab and...
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Korozja i wnikanie wodoru do stali 26H2MF
PublicationPrzedstawiono wyniki badań korozyjnych wykonanych technikami potencjodynamiczną oraz impedancyjną w roztworach kwasu siarkowego o różnym stężeniu i w paliwie ciężkim dla stali stopowej. Stwierdzono, że mechanizm korozji i jej szybkość zależą wyraźnie od środowiska. Wykazano, że ilość wnikającego wodoru jest wystarczająca do uzyskania stężenia niezbędnego do przebiegu procesu pękania wodorowego.
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Stirling engines - the state of technology development and computational models
PublicationStirling engines represent a technologically important solution in combined heat and power systems. Their use enables the achievement of over 90 percent efficiency in the management of the primary energy source with a very high durability of the device, mainly due to the lack of contact of the working gas with external factors and a very small number of mechanical components. The use of a Stirling engine may be equally important...
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Kinetic analysis of the stage for a high speed steam turbine
PublicationThis article analyzes possibilites of resonances within a control stage for a high speed steam turbine. This stage hase been based on assembling of a single blade to a rotating disk and increasing of rigidity of the system by using of a bandage. In the analysis will be nd a possiblity of resonance frequency, and mistuning by showing safety working ranges. The calculations have bean used the3D modal and harmonic analysis by the...
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Analytical eco-scale for assessing the greenness of analytical procedures
PublicationWe propose the analytical eco-scale as a novel comprehensive approach to evaluating the greenness of analytical methodology. It is based on assigning penalty points to parameters of an analytical process that are not in agreement with the ideal green analysis. This approach compares different parameters and different steps of the analytical process. Traditional green chemistry metrics 9e.g. Atom Economy, E-factor and Reaction Mass...
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Non-aqueous Fracturing Technologies for Shale Gas Recovery
PublicationTechnologie szczelinowania wykorzystywane podczas wydobycia gazu z łupków zostały rozwinięte głównie w USA i są obecnie przystosowywane do warunków geologicznych i wymagań ekologicznych w innych państwach. Praca przedstawia literaturę na temat teoretycznych i praktycznych aspektów wydobycia gazu z łupków z naciskiem na technologie alternatywne do szczelinowania hydraulicznego. Rozpatrzono również techniczne i środowiskowe aspekty...
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Pękanie zimne stali spawanej w środowisku wodnym
PublicationW pracy scharakteryzowano zagrożenia spawalności stali konstrukcyjnych związane z przeniesieniem spawania do środowiska wodnego. Przedstawiono stan wiedzy oraz wyniki własnych prac badawczych dotyczących wpływu warunków i parametrów spawania najczęściej stosowanymi pod wodą procesami na wrażliwość do pękania zimnego stali konstrukcyjnych. Zwrócono uwagę na aktualne trendy badawcze oraz nieścisłości w informacjach związanych z rozpatrywanymi...
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Profitable areas in large-scale FTTH network optimization
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Effect of power frequency on the stress state of disc actuator
PublicationThe paper presents the concept of determinig the optimum frequency of coil supply in inductive-dynamic drive. As a criterion to obtain the sought frequency, the smallest value of reduced stress in the disc was assumed while maintaining the desired dynamics.
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Improving Effectiveness of SVM Classifier for Large Scale Data
PublicationThe paper presents our approach to SVM implementation in parallel environment. We describe how classification learning and prediction phases were pararellised. We also propose a method for limiting the number of necessary computations during classifier construction. Our method, named one-vs-near, is an extension of typical one-vs-all approach that is used for binary classifiers to work with multiclass problems. We perform experiments...
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Zagrożenia korozyjne stali nierdzewnych w przemyśle spozywczym
PublicationPrzedstawiono przyczyny występowania zagrożeń korozyjnych stali nierdzewnych w przemyśle spożywczym. Szczegółowo omówiono mechanizm oraz sposób zapobiegania korozji wżerowej, szczelinowej oraz pękania korozyjnego. Zaprezentowano dokumentację fotograficzną omówionych typów korozji. Wskazano podstawowe problemy związane z doborem materiałów konstrukcyjnych do budowy instalacji w przemyśle spożywczym.
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Carbon dioxide fracturing technologies for shale gas recovery
PublicationThis paper presents literature survey on the theoretical and practical aspects of gas production from shale using carbon dioxide fracturing. Development of technical and environmental aspects of carbon dioxide fracturing technologies are also considered. Patents applicable to carbon dioxide fracturing are reviewed.
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On the internal efficiency of a turbine stage: classical and CFD definitions
PublicationAlmost entire fleet of steam turbines in Poland was designed between 1950 – 1980 with the use of the so-called zero dimensional (0D) calculation tools. For several years, design and modernization of the turbines occur in assistance with the state of the art methods that describe working fluid flow field based on 3D models and CFD codes. This cooperation between 0D and 3D codes requires exchange of overall, integral information...
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Carbon dioxide sequestration during shale gas recovery
PublicationThis paper presents literature on theoretical and practical aspects of gas production from shale using carbon dioxide fracturing. Development of technical and environmental aspects of carbon dioxide fracturing technologies is also considered. Patents applicable to carbon dioxide fracturing are reviewed. There were also conducted researches to evaluate possibility of carbon dioxide sequestration in shale gas reservoirs.
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Environmental aspects of shale gas recovery in Baltic Basin
PublicationFactors limiting shale gas exploration and exploitation in Pomorskie Voivodeship are presented. In particular, ground and surface water availability and land/community impact is discussed. Production from unconventional reservoirs requires proper well completion through hydraulic fracturing, hence voluminous streams of water are needed – in total 8000 to 20000 m3 per 1000 m of borehole length. 17 major groundwater basins were characterized....
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Wettability of shale rock as an indicator of fracturing fluid composition
PublicationShales have become one of the main unconventional gas resources in the world. However, physicochemical properties of rocks are still at the center of research. There have been conducted major researches in wettability of shales by fluids and advances in understanding and control of shale rock wettability. Also influence of interfacial phenomena on a production capacity of reservoirs have been made. The aim of this study is to find...
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PROBLEMY SPAWANIA PODWODNEGO STALI O PODWYŻSZONEJ WYTRZYMAŁOŚCI
PublicationW artykule scharakteryzowano obecnie stosowane techniki spawania podwodnego oraz problemy związane z uzyskiwaniem złączy o wymaganych własnościach. Przedstawiono wyniki badań spawalności stali o podwyższonej wytrzymałości w warunkach podwodnych. Wskazano główne kierunki badawcze oraz rozwój technologii spawalniczych zmierzających do ograniczenia wpływu niekorzystnych warunków spawania podwodnego oraz poprawy jakości złączy wykonywanych...
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Nagniatanie ślizgowe stali hartowanej Cf53 kulkami ceramicznymi
PublicationCeramika techniczna dostępna na rynku a stosowana na ostrza skrawające mogłaby być używana również na elementy robocze narzędzi nagniatających. Duża twardość tych materiałów jest korzystna natomiast inne właściwości fizyczne w tym parametry struktury geometrycznej powierzchni powodują, że nie zawsze są właściwym materiałem na elementy robocze w procesie nagniatania materiałów hartowanych. W tym artykule przedstawiono wyniki badań...
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Planning and Management of Large Scale Urban Development Projects
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Effect of power frequency on the stress state of disc actuator
PublicationThis paper presents the concept of determining the optimum frequency of coil supply in inductive-dynamic drive. As a criterion to obtain the sought frequency, the smallest value of reduced stress in the disc was assumed while maintaining the desired dynamics. The disc stress is determined on the basis of solution of vibrating thin plate equation. Magnetic pressure acting on the disc is obtained from a hybrid circumferentially-field...
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A Concept of Modeling and Optimization of Applications in Large Scale Systems
PublicationThe chapter presents the idea that includes modeling and subsequent optimization of application execution on large scale parallel and distributed systems. The model considers performance, reliability and power consumption. It should allow easy modeling of various classes of applications while reflecting key parameters of both the applications and two classes of target systems: clusters and volunteer based systems. The chapter presents...
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Modelowanie dynamiki warstwy gruntu na stole sejsmicznym
PublicationPodsumowano wyniki badań warstwy gruntu sypkiego na stole sejsmicznym. Pierwsza grupa badań dotyczyła analizy osiadań warstwy gruntu suchego, poddanego poziomym drganiom o zadanej częstości i amplitudzie przyspieszenia, głównie harmonicznego. Druga grupa badań dotyczyła dynamiki warstwy nawodnionego gruntu, przy ustalonej amplitudzie poziomego przyspieszenia oraz różnych częstościach. Opisano same doświadczenia, podsumowano najważniejsze...
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Simulation of Parallel Applications on Large-scale Distributed Systems
PublicationThis chapter has a form of a review article in the field of simulating High-Performance Computing systems. We justify the need for a new versatile simulator considering heterogeneity, energy efficiency and reliability of HPC systems. We sketch the problems that need to be solved by such simulator and rationalize using discrete-event simulation for this purpose. Based on a review of existing discrete-event HPC simulation solutions...
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Potentiometric Oxygen Sensor with Solid State Reference Electrode
PublicationThe concentration or the partial pressure of oxygen in an environment can be determined using different measuring principles. For high temperature measurements of oxygen, ceramic-based sensors are the most practical. They are simple in construction, exploration and maintenance. A typical oxygen potentiometric sensor consists of an oxygen ion conducting solid electrolyte and two electrodes deposited...
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Two Stage SVM and kNN Text Documents Classifier
PublicationThe paper presents an approach to the large scale text documents classification problem in parallel environments. A two stage classifier is proposed, based on a combination of k-nearest neighbors and support vector machines classification methods. The details of the classifier and the parallelisation of classification, learning and prediction phases are described. The classifier makes use of our method named one-vs-near. It is...
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Badania złączy lutowanych próżniowo ze stali austenitycznej
PublicationCelem badań była ocena poprawności budowy złącza lutowanego próżniowo ze stali austenitycznej 316L oraz analiza składu chemicznego charakterystycznych obszarów badanej próbki. Na podstawie badań wizualnych oraz metalograficznych na mikroskopie skaningowym (w tym analizy EDS) stwierdzono, że badane złącze charakteryzuje się dużym nasileniem występowania niezgodności, co wynika z silnej segregacji dendrytycznej pierwiastków stopowych....
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Analysis of transformer state by fuzzy TOPSIS and AHP method
PublicationThe paper presents mathematical models TOPSIS and AHP methods, which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine the importance of these measurements methods with this mathematical apparatus in these measurements methods in insulating state of transformers.
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Ocena jakości złączy lutowanych ze stali austenitycznej
PublicationCelem badań była ocena poprawności budowy złącza lutowanego próżniowo ze stali austenitycznej 316L oraz analiza składu chemicznego charakterystycznych obszarów badanej próbki. Na podstawie badań wizualnych oraz metalograficznych na mikroskopie skaningowym (w tym analizy EDS) stwierdzono, że badane złącze charakteryzuje się prawidłową budową i nielicznymi niezgodnościami zlokalizowanymi w pobliżu lica lutowiny. Wyniki analiz EDS...
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State observers for diagnostic applications in modern electric traction
PublicationW rozdziale 7 monografii przedstawiono zagadnienie diagnostyki czujnika prędkości silnika i przekładni mechanicznej pociągu. Przedstawiono zagadnienia związane z diagnostyką czujnika prędkosci obrotowej silnika oraz układu transmisjii momentu trakcyjnego. Do diagnostyki wykorzystano analizę sygnałów prędkości obrotowej i momentu obciążenia silnika obliczanych przez układy obserwatorów stanu. Analiza chwilowych wartości obliczonej...
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State of the art electronic nose technology and future trends
PublicationThis chapter briefly reviews the progress in field of artificial olfaction and demonstrates future trends in electronic nose technology. The discussion about e-nose concern also a big challenge for the pattern recognition (PARC) systems due to several particular problems they involve. Finally, the application of e-nose in different areas of life is given.
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Human subarachnoid space width oscillations in the resting state
PublicationAbnormal cerebrospinal fluid (CSF) pulsatility has been implicated in patients suffering from various diseases, including multiple sclerosis and hypertension. CSF pulsatility results in subarachnoid space (SAS) width changes, which can be measured with near-infrared transillumination backscattering sounding (NIR-T/BSS). The aim of this study was to combine NIR-T/BSS and wavelet analysis methods to characterise the dynamics of the...
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Analytical Steady-State Model of the Pipeline Flow Process
PublicationThe paper addresses the issue of modeling the flow process in transmission pipelines. A base model used for numerical simulation is introduced. Under certain assumptions concerning steady state analysis, the differential equations describing the process are solved analytically for two cases: zero and nonzero inclination angle α. These equations describe a constant flow rate and a corresponding distribution of the pressure along...
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The Use of Free Adjustment and Msplit-Estimation for Determination of the Vertical Displacements in Unstable Reference System
PublicationThe problem of the determining of the displacements of engineering objects and their surroundings is the current and important issue in the field of engineering geodesy. Most control measurements are made in relation to reference points (stable points). On the other hand, sometimes it happens that it is not possible perform the measurements with reference to the stable points or identification of stable points is difficult. Therefore,...
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Ptasie pióra jako biomonitory do uzyskiwania informacji o stanie środowiska
PublicationWzrost antropopresji sprawia, że do poszczególnych elementów ekosystemów emitowane są duże ilości różnych ksenobiotyków. W efekcie konieczne jest stałe monitorowanie poziomu zawartości ekotoksyn w poszczególnych elementach środowiska wykorzystując procedury analityczne charakteryzujące się odpowiednimi parametrami metrologicznymi, takimi jak: duża precyzja i dokładność, mała wartość liczbowa granicy oznaczalności i wykrywalności...
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Identification of Unstable Reference Points and Estimation of Displacements Using Squared Msplit Estimation
PublicationThe article presents a new version of the method for estimating parameters in a split functional model, which enables the determination of displacements of geodetic network points with constrained datum. The main aim of the study is to present theoretical foundations of Msplit CD estimation and its basic properties and possible applications. Particular attention was paid to the efficacy of the method in the context of geodetic...
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A strongly bound OF3- anion and its unstable parent neutral OF3 species
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Application ofMsplitestimation to determine control points displacements in networks with unstable reference system
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Toward a hybrid model of ship performance in ice suitable for route planning purpose
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Numeryczna analiza warstwy stochastycznego ośrodka gruntowego w płaskim stanie odkształcenia.
PublicationW pracy rozpatrzono warstwę gruntu spoczywającego na poziomym, nieodkształcalnym podłożu, poddaną zarówno obciążeniu od grawitacji jak i równomiernie rozłożonego pionowego obciążenia zewnętrznego. Obliczenia wykonano programem NONSAP adoptującym stochastyczną metodę elementów skończonych, bazującą na metodzie Monte Carlo. W programie wykorzystano algorytm symulacji pola losowego oparty na efektywnej wersji metody eliminacji i warunkowym...
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Recent Advances in Nanocomposite Membranes for Organic Compound Remediation from Potable Waters
PublicationWater treatment is one of the main approaches for producing drinking water from contaminated water sources which is challenging due to the presence of a variety of substances requiring removal. The fabrication of nanocomposite membranes relies either on filling nanomaterials into polymeric phases before membrane fabrication, or coating of nanomaterials on the fabricated membrane surface. The removal of organic compounds from potable...
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Application of passive sampling techniques as a usable tool in the field of environmental quality monitoring
PublicationAnalysis of literature data published for the past 20 years leads to the conclusion, that passive sampling technique has been developing very quickly and is commonly used in the field of monitoring pollutants in air, water and soil environment. The popularity of application of passive sampling techniques in analytical and environmental chemistry results from its many advantages e.g.: Simplicity in use, low costs of exploitation,...
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Interplay between Selected Chemical and Biochemical Soil Properties in the Humus Horizons of Grassland Soils with Low Water Table Depth
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Towards a universal embedded-atom method: empirically adjusted and consistent set of atomic densities for all elements of the periodic table
PublicationModel atomu HFS został zmodyfikowany poprzez wyznaczenie indywidualnych parametrów αex dla atomów. Parametry αex wyznaczono w oparciu o energię jonizacji atomów. W oparciu o tak zmodyfikowaną metodę HFS wyznaczono rozkłady gęstości elektronów w atomach.
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Limiting distribution of the three-state semi-Markov model of technical state transitions of ship power plant machines and its applicability in operational decision-making.
PublicationThe article presents the three-state semi-Markov model of the process {W(t): t 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application...
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Weak Stability of Centred Quadratic Stochastic Operators
PublicationWe consider the weak convergence of iterates of so-called centred quadratic stochastic operators. These iterations allow us to study the discrete time evolution of probability distributions of vector-valued traits in populations of inbreeding or hermaphroditic species, whenever the offspring’s trait is equal to an additively perturbed arithmetic mean of the parents’ traits. It is shown that for the existence of a weak limit, it...
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The state of the art in the field of decrease the pollution in the South Baltic area
PublicationVarious form of human activity such as maritime transports, industrial activities, busy traffic, intensive farming and animal husbandry can have negative impact on natural marine environment. Baltic Sea catchment area is characterized by the high river water flux and wastewater treatment plants discharges. Additionally, the limited shallow connection to the North Sea results in little water exchange and residence time of approximately...
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Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods
PublicationHigh precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most...
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OBTAINING FLUID FLOW PATTERN FOR TURBINE STAGE WITH NEURAL MODEL.
PublicationIn the paper possibility of applying neural model to obtaining patterns of proper operation for fluid flow in turbine stage for fluid-flow diagnostics is discussed. Main differences between Computational Fluid Dynamics (CFD) solvers and neural model is given, also limitations and advantages of both are considered. Time of calculations of both methods was given, also possibilities of shortening that time with preserving the accuracy...
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Properties and Formation of Mineralized Veins in an Organic-Rich Shale Formation
PublicationAn earlier paper defined mineral and organic matter constituents in weak interfaces in shale formations (Ptaszynska, et. al., 2016). The formation studied in the earlier work and here is the Jurassic, early-Cretaceous Vaca Muerta formation in the Neuquen basin in Argentina. In this earlier work, mineralized "veins" were noted to be prevalent and complicated, sometimes being shear weak interfaces while in other cases they were not....
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PU Polymers, Their Composites, and Nanocomposites: State of the Art and New Challenges
PublicationThe chapter is a review of the polyurethane(PU)-based composites and nanocomposites. The chapter details different components in the manufacturing of PU polymers, composites, and nanocomposites. The different types of glycols, isocyanates, and catalysts that are used for the synthesis of different polyurethanes are discussed. The applications and specialties of polyurethane composites and nanocomposites are also elaborated on.