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Search results for: VARIATION OF HAT PROBLEM
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Metody ochrony przed spoofingiem w systemach nawigacji satelitarnej GNSS
PublicationPrzedstawiono problem spoofingu w systemach nawigacji satelitarnej. Dokonano przeglądu metod wykrywania i eliminacji spoofingu. Ponadto, przedstawiono wyniki badań rozwiązania antyspoofingowego opartego na przestrzennym przetwarzaniu sygnałów.
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Adjusted SpikeProp algorithm for recurrent spiking neural networks with LIF neurons
PublicationA problem related to the development of a supervised learning method for recurrent spiking neural networks is addressed in the paper. The widely used Leaky-Integrate-and-Fire model has been adopted as a spike neuron model. The proposed method is based on a known SpikeProp algorithm. In detail, the developed method enables gradient descent learning of recurrent or multi-layer feedforward spiking neural networks. The research included...
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A note on compact and compact circular edge-colorings of graphs
PublicationW pracy rozważamy dwa warianty kolorowania krawędzi grafów prostych i ważonych, mianowicie kolorowania zwarte oraz zwarte cyrkularne. Rozważamy relacje pomiędzy nimi. Dowodzimy, że każdy zewnętrznie planarny graf dwudzielny posiada zwarte pokolorowanie krawędziowe oraz, że problem ten dla grafów ogólnych jest NP-zupełny. Podajemy również wielomianowy 1.5-przybliżony algorytm oraz pseudowielomianowy dokładny algorytm zwartego cyrkularnego...
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System zarządzania naprawami
PublicationW artykule tym opisano dwa istotne współcześnie problemy, związane z wykorzystywaniem w przemyśle systemów IT: problem ich monitorowania oraz problem ich naprawy. Przedstawiono w nim skrótowo wytworzone rozwiązanie, służące automatyzacji procesu przeprowadzania napraw oraz integrujące się z istniejącymi systemami monitorującymi. Rozwiązanie to, zwane Systemem Zarządzania Naprawami, jest częścią większej metody, zwanej Metodą Zarządzania...
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Advanced Ship Control Methods
PublicationThe chapter presents two main streams of research in vessel control at sea: dynamic positioning (DP) of the vessel and decision support in case of collision at sea. The control structure and basic requirements for the DP system are defined. Selected issues of automatic control of a dynamically positioned vessel are discussed. A review of advanced methods of controlling a DP ship is carried out, taking into account the tasks of...
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Numerical conditioning of delta-domain Lyapunov and Riccati equations
PublicationW pracy rozważono problem uwarunkowania dyskretno czasowych równań Lapunowa oraz równań Riccatiego - to znaczy problem wrażliwości rozwiązań takich równań na odchyłki ich parametrów od nominalnych wartości. Zdefiniowano odpowiedni "różniczkowy" wskaźnik uwarunkowania oraz podano efektywną metodę szacowania jego wartości. Udowodniono teoretycznie - a także przekonująco zilustrowano na drodze numerycznej - twierdzenie głoszące, iż...
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A novel genetic approach to provide differentiated levels of service resilience in IP-MPLS/WDM networks
PublicationThis paper introduces a novel class-based method of survivable routing for connection-oriented IP-MPLS/WDM networks, called MLS-GEN-H. The algorithm is designed to provide differentiated levels of service survivability in order to respond to varying requirements of end-users. It divides the complex problem of survivable routing in IP-MPLS/WDM networks into two subproblems, one for each network layer, which enables finding the...
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Modeling SPMD Application Execution Time
PublicationParallel applications in a Single Process Multiple Data paradigm assume splitting huge amounts of data to multiple processors working in parallel at small data packets. As the individual data packets are not independent, the processors must interact with each other to exchange results of the calculations with their adjacent partners and take these results into account in their own computations. An example of SPMD is geometric parallelism...
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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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Evaluation of position estimation based on accelerometer data
PublicationThe paper concerns the problem of integrating data from accelerometers. A suitable model of a MEMS accelerometer is presented which is a part of inertial measurement units (IMU). Such units allow to measure orientation as well as to localize systems. They also appear to be applicable for systems positioning. The main purpose of the paper is to discuss conditions that must be satisfied to calculate the location of the sensor by...
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Optimal asynchronous estimation of 2D Gaussian-Markov processes
PublicationW artykule rozważa się problem estymacji trajektorii dwuwymiarowych ciągłoczasowych procesów Gaussa-Markowa na podstawie zaszumionych pomiarów wykonywanych w nierównomiernie rozłożonych chwilach czasu. W przypadku takiego problemu, w każdym cyklu pracy algorytmu należy dokonać dyskretnoczasowej predykcji (analogicznie jak w przypadku filtru Kalmana). Niestety zadanie to może być złożone obliczeniowo. Aby rozwiązać ten problem,...
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Discrimination of workers aged 55+ in companies in Poland
PublicationThe problem of discrimination on the grounds of age in the workplace is particularly topical not only in Poland but also in Europe as a whole. The paper presents the essence of the discrimination and its most common manifestations. The results of own research on the youngPoles' perception of the discrimination on grounds of age in the workplace, intergenerational competition in the labour market and some of the factors shaping...
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Arctic Freshwater Environment Altered by the Accumulation of Commonly Determined and Potentially New POPs
PublicationChemical composition of Arctic freshwater ecosystems depends on several factors. They include characteristics of the surrounding landscape, its lithology, geomorphology, vegetation, and hydrological features, as well as accumulation of anthropogenic pollution. In the Arctic, the problem of environmental contamination is widespread. That is why research on lakes and river catch-ments in terms of their chemical composition has enjoyed...
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Harmonic Vibrations of Nanosized Magnetoelectric Bodies with Coupled Surface and Interphase Effects: Mathematical Models and Finite Element Approaches
PublicationThe harmonic problems for piezomagnetoelectric nanosized bodies with taking into account the coupled damping and surface effects are considered on the base of the generalized Gurtin-Murdoch model. In the development of previous investigations, the coupled mechanical, electric and magnetic surface effects with surface inertial terms are introduced into the model. For a homogeneous model, the composite material is considered as homogeneous...
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Main complications connected with detection, identification and determination of trace organic constituents in complex matrix samples
PublicationIt is well known that some problems with the determination of organic analytes at trace level can occur. This issue is connected with contamination during each stage of the analytical procedure from sampling to sample preparation up to chromatographic analysis, which often leads to false-positive or overestimated results. Another problem associated with determination of analytes occurs at trace- and ultra-trace level is a background...
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Selection of optimal location and rated power of capacitor banks in distribution network using genetic algorithm
PublicationIn this paper, the problem of placement and rated power of capacitor banks in the Distribution Network (DN) is considered. We try to suggest the best places for installing capacitor banks and define their reactive power. The considered formulation requires the optimization of the cost of two different objectives. Therefore the use of properly multiobjective heuristic optimization methods is desirable. To solve this problem we use...
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Risk assessment for tram traffic on tramway bridges
PublicationMiejski transport szynowy wielu miastach stanowi istotny element systemu transportowego i jest przestrzennie rozwijającym się systemem zapewniającym mieszkańcom codzienną obsługę transportową. Bezpieczeństwo pasażerów transportu szynowego i użytkowników dróg jest jednym z najważniejszych czynników, który należy uwzględnić w trakcie projektowania infrastruktury oraz w ocenie operacyjnej systemu miejskiego transportu tramwajowego....
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Scheduling with Complete Multipartite Incompatibility Graph on Parallel Machines
PublicationIn this paper we consider a problem of job scheduling on parallel machines with a presence of incompatibilities between jobs. The incompatibility relation can be modeled as a complete multipartite graph in which each edge denotes a pair of jobs that cannot be scheduled on the same machine. Our research stems from the works of Bodlaender, Jansen, and Woeginger (1994) and Bodlaender and Jansen (1993). In particular, we pursue the...
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Using similar classification tasks in feature extractor learning
PublicationThe article presents and experimentally verify the idea of automatic construction of feature extractors in classification problems. The extractors are created by genetic programming techniques using classification examples taken from other problems then the problem under consideration.
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On the mechanisms of soil remediation with use of surfactants
PublicationPrzedstawiono problem zanieczyszczenia gruntów substancjami olejowymi. Zaprezentowano metodę remediacji za pomocą przemywania roztworami surfaktantów. Omówiono mechanizmy biorące udział w usuwaniu zanieczyszczeń z gruntu podczas tego procesu.
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Praktyczne problemy doboru kanalizacyjnej studzienki rewizyjnej
PublicationAnaliza problemów związanych z właściwym dla określonych warunków doborem kanalizacyjnej studzienki rewizyjnej. Podstawowa kategoryzacja obiektów. Problemy poszczególnych grup konstrukcyjnych, konieczne wzmocnienia. Problem sprecyzowania szczególnych warunków zamówienia.
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Studzienka rewizyjna z tworzywa
PublicationSzczególne wymagania kanalizacyjnych studzienek z tworzyw sztucznych. Specyfika konstrukcji z tworzyw termoplastycznych. Problem wyboru rozwiązania, deklaracja na poziomie Specyfikacji Istotnych Warunków Zamówienia. Kategorie normowe, deklaracja producenta
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(Wywiad z…)Woda musi być od prowadzana szybko i skutecznie
PublicationWypowiedź na temat skuteczności odwodnienia drogowego w Polsce. Identyfikacja głównych problemów, przyczyn braku skutecznosci. Problem zbędnych kosztów. Konserwatyzm środowisk projektantów i inwestorów. Sprawność techniczna stosowanych rozwiązań.
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Ogólne warunki procesu inwestycyjnego
PublicationSpecyficzne warunki realizacji procesu inwestycyjnego. Wymagania formalne. Zagadnienie inwestycji nietypowych, potrzeba zewnętrznego fachowego nadzoru. Podstawowe błędy na etapie projektowania i wykonawstwa. Problem wiarygodności inspektora nadzoru inwestorskiego.
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Bifurcation of equilibrium forms of a gas column rotating with constant speed around its axis of symmetry
PublicationWe will be concerned with the problem of deformation of the lateral surface of a column that rotates with constant speed around its axis of symmetry. The column is filled by a gas and our goal is to investigate the deformation of the lateral surface depending on the pressure of the gas.
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Cztery algorytmy, które wstrząsnęły światem. Część III: Sprzęt czy oprogramowanie
PublicationW ostatniej części tryptyku poruszamy problem przyjaznego rysowania grafów oraz prezentujemy algorytmy dla szybkiego mnożenia macierzy. Nasze rozważania kończymy ilustracją postępu w dziedzinie sprzętu i oprogramowania
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Perceptions of Gender Diversity's Impact on Mood in Software Development Teams
PublicationGender inequality persists in IT teams. We examine how gender differentiation affects the workplace atmosphere and analyze the results of our study of the issue. We discuss the problem of gender discrimination and consider methods to reduce inequality
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Organohalogen compounds in the environment.
PublicationPrzedyskutowano problem związków chloroorganicznych w środowisku, takich jak: pestycydy chloroorganiczne, polichlorowane bifenyle, polichlorowane dibenzodioksyny i furany. Omówiono podstawowe właściwości fizykochemiczne, toksykologiczne oraz ścieżki przemian w środowisku.
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Swobodny przepływ pracowników w UE
PublicationW rozdziale zaanalizowano zagadnienia związane z prawem swobodnego przepływu osób w UE i związanego z nim swobodnego wyboru miejsca pracy. Poruszono także problem bezpieczeństwa obywateli UE.
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Packing three-vertex paths in a subcubic graph
PublicationW pracy rozważany jest problem pakowania scieżek P3 w grafach podkubicznych, pokazano oszacowania dolne na ilość ścieżek w zależności od stopnia spójności grafu oraz minimalnego stopnia.
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Measurements of raising of 160EC pantograph type
Open Research DataIn this description the results of the experiment and also simulation performed on the total assembly of the 160 EC pantograph type is given. Multibody dynamics of pantograph rising due to external torque and forces are measured for parameter validation of the pantograph model.
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Dissimilar autogenous TIG joint of Alloy 617 and AISI 304H steel for AUSC application
PublicationTo reduce costs and improve high-temperature performance in Advanced Ultra Super Critical (AUSC) boilers, it is necessary to weld austenitic steel to Inconel alloy. In this study, the autogenous tungsten inert gas (TIG) welding process was used to join Alloy 617 and an austenitic AISI 304H steel plate of thickness 5 mm. Microstructural analysis showed that the microstructure formation was uneven along the weldments, with columnar...
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Impedimetric sensing of α-amino acids driven by micro-patterned 1,8-Diazafluoren-9-one into titania- boron- doped maze-like nanocarbons
PublicationThe development of impedimetric, non-faradaic label-free sensors for the detection of α-amino acids constitutes a trailblazing technology for the fast and inexpensive quantification of such biomarkers. Since α-amino acids, such as glycine and sarcosine, are basic constituents in biological processes, a variation in their concentration may be an indicator of cardiovascular diseases and metabolic disorders or neurological conditions....
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Local variability in snow concentrations of chlorinated persistent organic pollutants as a source of large uncertainty in interpreting spatial patterns at all scales
PublicationSingle point sampling, a widespread practice in snow studies in remote areas, due to logistical constraints, can present an unquantified error to the final study results. The low concentrations of studied chemicals, such as chlorinated persistent organic pollutants, contribute to the uncertainty. We conducted a field experiment in the Arctic to estimate the error stemming from differences in the composition of snow at short distances...
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Three modes of electrochemical impedance spectroscopy measurements performed on vanadium redox flow battery
PublicationThis article presents an innovative approach to monitor working redox flow batteries using dynamic electrochemical impedance spectroscopy, diverging from the commonly sequential impedance methods carried out under potentiostatic or galvanostatic conditions close to the open circle voltage. The authors introduce a fresh variation of dynamic impedance measurement that leverages an amplitude-modulated multi-frequency alternating current...
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Corrosion damage identification based on the symmetry of propagating wavefield measured by a circular array of piezoelectric transducers: Theoretical, experimental and numerical studies
PublicationThe article investigates the results obtained from numerical simulations and experimental tests concerning the propagation of guided waves in corroded steel plates. Developing innovative methodologies for assessing corrosion-induced degradation is crucial for accurately diagnosing offshore and ship structures exposed to harsh environmental conditions. The main aim of the research is to analyze how surface irregularities affect...
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Curing characteristics, mechanical properties and morphology of butyl rubber filled with ground tire rubber (GTR)
PublicationThe results on testing application of ground tire rubber (GTR), as potential filler for butyl rubber, are pre- sented. The GTR content variation, within the range of 10–90 phr, was studied with respect to the vulcanization process, static mechanical properties (tensile strength, elongation-at-break, hardness and resilience), dynamic mechanical properties and the morphology of the obtained vulcanizates. Butyl rubber was characterized...
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Improving the procedure of probabilistic load testing design of typical bridges based on structural response similarities
PublicationThis paper concerns load testing of typical bridge structures performed prior to operation. In-situ tests of a two-span post-tensioned bridge loaded with three vehicles of 38-ton mass each formed the input of this study. On the basis of the results of these measurements, an advanced FEM model of the structure was developed for which the sensitivity analysis was performed for chosen uncertainty sources. Three uncorrelated random...
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Probabilistic analysis of settlements under a pile foundation of a road bridge pylon
PublicationThe paper addresses the reliability change of a road bridge pile foundation due to the unpredictable increase of settlements in time. The analysis is based on the Rędziński Bridge in Wrocław, Poland, its design assumptions, and monitoring results. The bridge foundation rests on a multi-layered subsoil assumed random. The Finite Element model of the subgrade is generated in ZSoil® software. To simplify the probabilistic approach,...
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Application of different building representation techniques in HEC-RAS 2-D for urban flood modeling using the Toce River experimental case
PublicationThis paper presents the impact of the choice of building representation techniques and hydrodynamic models on urban flood simulations using HEC-RAS 2-D for the Toce River physical model. To this end, eight numerical models based on previous laboratory experiments were prepared to simulate unsteady urban flooding on each side of building units. Two simplified building layouts (aligned and staggered) were examined, where models were...
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Multi-objective optimization of the cavitation generation unit structure of an advanced rotational hydrodynamic cavitation reactor
PublicationHydrodynamic cavitation (HC) has been widely considered a promising technique for industrial-scale process intensifications. The effectiveness of HC is determined by the performance of hydrodynamic cavitation reactors (HCRs). The advanced rotational HCRs (ARHCRs) proposed recently have shown superior performance in various applications, while the research on the structural optimization is still absent. The present study, for the...
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The impact of freeze-thaw processes on a cliff recession rate in the face of temperate zone climate change
PublicationFreeze-thaw action is a common type of geomorphological processes eroding cliff faces in the temperate climate zone. In our previous study, we assessed the geomorphological effects of freeze-thaw fluctuations occurring within the cliff of Jeziorsko Reservoir (central Poland). Based on those findings, we have now determined the number of freeze-thaw cycles to assess their historical impact on the studied cliff. We have also traced...
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On the generalized model of shell structures with functional cross-sections
PublicationIn the present study, a single general formulation has been presented for the analysis of various shell-shaped structures. The proposed model is comprehensive and a variety of theories can be used based on it. The cross-section of the shell structure can be arbitrarily analyzed with the presented equations. In other words, various types of shell structures, including cylindrical, conical, spherical, elliptical, hyperbolic, parabolic,...
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Mild X-linked Alport syndrome due to the COL4A5 G624D variant originating in the Middle Ages is predominant in Central/East Europe and causes kidney failure in midlife
PublicationA study of 269 children enrolled into a National Registry for children with persistent glomerular hematuria identified 131 individuals with genetically confirmed X-linked Alport Syndrome. A single variant c.1871G>A p.Gly624Asp (G624D) in COL4A5 was predominant and accounted for 39% of Xlinked Alport Syndrome in unrelated Polish families (44 of 113). To evaluate its origins, the genetic variation in a 2.79 Mb segment encompassing...
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Ultrasound-Assisted Solvent Extraction of a Porous Membrane Packed Sample for the Determination of Tobacco-Specific Nitrosamines in the Replacement Liquids for E-Cigarettes
PublicationThe content of tobacco-specific nitrosamines (TSNAs) possessing carcinogenic properties has been an important area of research since replacement liquids were introduced for e-cigarettes. A method for determining N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT), and N′-nitrosoanabasine (NAB) in replacement liquids for electronic cigarettes was developed using liquid chromatography–tandem...
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Organic Acids and Polyphenols Determination in Polish Wines by Ultrasound-Assisted Solvent Extraction of Porous Membrane-Packed Liquid Samples
PublicationIn the near future, Poland is going to have more and more favorable conditions for viticulture. Organic acids and polyphenols are among the most commonly analyzed compounds due to their beneficial properties for human health and their importance in the winemaking process. In this work, a new technique involving ultrasound-assisted solvent extraction of porous membrane-packed liquid samples (UASE-PMLS) was for the first time described...
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Heterogeneous oxidation of highly boron-doped diamond electrodes and its influence on the surface distribution of electrochemical activity
PublicationThe electrochemical active surface area (EASA) of polycrystalline boron-doped diamond (BDD) electrodes is heterogeneous and can be affected by numerous factors. There is a strong need for proper consideration of BDD heterogeneity in order to improve this material's range of application in electrochemistry. Localized changes in surface termination due to the influence of oxidation agent result in increased surface resistance. The...
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The possibility of estimating the height of the ionospheric inhomogeneities based on TEC variations maps obtained from dense GPS network
PublicationA state of the ionosphere can be effectively studied using electromagnetic signals received from global navigation satellite systems (GNSS). Utilization of the dual frequency observations allows estimating values of the total electron content (TEC). They can be used for a number of scientific studies such as detection and monitoring of traveling ionospheric disturbances or plasma bubbles. Moreover, maps of TEC variations allow...
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Thermal and physical properties of ZrO2–AlO(OH) nanopowders synthesised by microwave hydrothermal method
PublicationIndustrially relevant nanopowder was synthesised by microwave hydrothermal synthesis to obtain well-controlled composition (ZrO2–AlO(OH) system) which was found to determine a number of physical and thermal characteristics. This study reports variation of particle size, density, specific surface area (SSABET), as well as thermal behaviour of nanopowder mixtures of ZrO2–AlO(OH) in the whole range of compositions. It was found that...
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Influence of initial density of cohesionless soil on evolution of passive earth pressure
PublicationArtykuł porusza problem odporu bezkohezyjnego gruntu. Obliczenia wykonano wykorzystując metodę elementów skończonych na bazie mikropolarnego prawa hipolastycznego. W obliczeniach przyjęto różne początkowe zagęszczenia oraz średnice cząstek gruntu.