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Search results for: SNOW COVER STABILITY
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Influence of the shoe type on the ground reaction forces
PublicationThe aim of this work was to estimate a relationship between the type of the footwear and ground reactions. Differences in medio-lateral, anterior-posterior and vertical reactions are compared for different shoe-types for male and female volunteers. Each of the participants gait was recorded in case of different shoes and without them, also stabilograms were analyzed. Results revealed differences in ground reaction forces for different...
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Selected issues related to the toxicity of ionic liquids and deep eutectic solvents—a review
PublicationGreen Chemistry plays a more and more important role in implementing rules of sustainable development to prevent environmental pollution caused by technological processes, while simultaneously increasing the production yield. Ionic liquids (ILs) and deep eutectic solvents (DESs) constitute a very broad group of substances. Apart from many imperfections, ILs and DESs have been the most promising discoveries in the world of Green...
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Application of deep eutectic solvents for separation and determination of bioactive compounds in medicinal plants
PublicationThe medicinal plants industry, particularly in regard to products rich in biologically active substances for maintaining health, has grown by leaps and bounds in the last decade, with sales of over-the-counter drugs containing these substances growing by billions of dollars. Attention has thus also been paid to the safety and effectiveness of these medicines. We are currently witnessing a rapid increase in the number of publications...
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Overcoming gender bias in the digital economy. Empirical evidence for European countries
PublicationThis study aims to contribute to understanding the gender biases that emerge in the digital technology-related field. More specifically we concentrate on examining whether gender gaps are diminishing or are persistent in terms of women’s enrollment in technology-related programs at the tertiary level of education and for female STEM graduates. Next, this evidence is confronted with gender biases in the labor market regarding changing...
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Modelling of some stealth features for a small navy ship at the concept design stage - part II
PublicationIn the paper a few problems associated with modelling the basic stealth features for a small ship at the concept design stage are introduced. One problem concerns the modification of the immersed ship hull using the rapid change of the ship loading condition. The second is associated with the modification of the ship boundary layer by the hull skin cover. The other stealth features of the ship are not presented in this paper. The...
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The role of stakeholders on rejection of bankruptcy applications in the case of “poverty” of the estate: A Polish case study
PublicationThe aim of this article is to supplement the Law and Economics area of science with regard to the scope of the ex ante effectiveness of bankruptcy law using the example of Poland. Bankruptcy law is effective in the ex ante stage when it eliminates from the market insolvent entrepreneurs who cannot even afford to cover the costs of bankruptcy proceedings. In these cases, the bankruptcy court should dismiss the petition for bankruptcy...
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Performance‐driven modeling of compact couplers in restricted domains
PublicationFast surrogate models can play an important role in reducing the cost of EM-driven design closure of miniaturized microwave components. Unfortunately, construction of such models is challenging due to curse of dimensionality and wide range of geometry parameters that need to be included in order to make it practically useful. In this letter, a novel approach to design-oriented modeling of compact couplers is presented. Our method...
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Towards Understanding of Mechanics of Hernia Managed by Synthetic Mesh in Laparoscopic Operation: A Single Case Study
PublicationIn this paper a research towards understanding of mechanics of ventral hernia operated with the use of Physiomesh Open image in new window implant and SecureStrap Open image in new window staples is described. Experimental and numerical studies are conducted for that purpose. Experimental works cover uni-axial tension tests of the implant samples and of the implant-staples-tissue system. Also experiments on implant-staples-tissue...
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Ship weather routing optimization with dynamic constraints based on reliable synchronous roll prediction
PublicationShip routing process taking into account weather conditions is a constrained multi-objective optimization problem and it should consider various optimization criteria and constraints. Formulation of a stability-related, dynamic route optimization constraint is presented in this paper. One of the key objectives of a cross ocean sailing is finding a compromise between ship safety and economics of operation. This compromise should...
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Giant Reed (Arundo donax L.) Fiber Extraction and Characterization for Its Use in Polymer Composites
PublicationThis work describes an extraction method for giant reed fibers from stems and leaves based on chemical soaking and crushing through a rolling mill. Obtained fibers, together with the shredded plant (stems + leaves), are characterized in terms of chemical composition, thermal stability, morphology, and crystallinity. Mechanical properties of fibers have also been assessed (single fiber tensile tests). The results show that the proposed...
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Thermal buckling of functionally graded piezomagnetic micro- and nanobeams presenting the flexomagnetic effect
PublicationGalerkin weighted residual method (GWRM) is applied and implemented to address the axial stability and bifurcation point of a functionally graded piezomagnetic structure containing flexomagneticity in a thermal environment. The continuum specimen involves an exponential mass distributed in a heterogeneous media with a constant square cross section. The physical neutral plane is investigated to postulate functionally graded material...
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Microplastics removal from aqueous environment by metal organic frameworks
PublicationThis paper provides an overview of recent research performed on the applications of metal–organic frameworks (MOFs) for microplastics (MPs) removal from aqueous environments. MPs pollution has become a major environmental concern due to its negative impacts on aquatic ecosystems and human health. Therefore, developing effective and sustainable methods for removing them from aqueous environments is crucial. In recent years, MOFs...
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A framework for onboard assessment and monitoring of flooding risk due to open watertight doors for passenger ships
PublicationPost-accident safety of ships is governed by damage stability, affected by watertight subdivisions which limit accidental flooding. This is important for passenger ships with watertight doors (WTDs) often fitted in the bulkheads. Awareness of the ship flooding risk due to open WTDs and the conditions under which the associated risk level changes are prerequisites for proactive risk mitigation. Accident risk is often expressed as...
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Extraction and evaluation of gas-flow-dependent features from dynamic measurements of gas sensors array
PublicationGas analyzers based on gas sensors are the devices which enable recognition of various kinds of volatile compounds. They have continuously been developed and investigated for over three decades, however there are still limitations which slow down the implementation of those devices in many applications. For example, the main drawbacks are the lack of selectivity, sensitivity...
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Ternary Bismuthide SrPtBi2: Computation and Experiment in Synergism to Explore Solid-State Materials
PublicationA combination of theoretical calculation and the experimental synthesis to explore the new ternary compound is demonstrated in the Sr–Pt–Bi system. Because Pt–Bi is considered as a new critical charge-transfer pair for superconductivity, it inspired us to investigate the Sr–Pt–Bi system. With a thorough calculation of all the known stable/metastable compounds in the Sr–Pt–Bi system and crystal structure predictions, the thermodynamic...
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Historical crane on the redesigned original trestle bridge as a memorial of Gdansk Shipyard
PublicationThe paper includes selected aspects of the study, whose goal is to hold the historical crane 642-24 in its current location after the modification of trestle bridge static scheme. The scope of the paper includes the assessment of current technical condition of the object, a presentation of FEM analyses, a description of the assumed load cases, results of the static calculations, checking the effort of construction elements, global...
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REALIZACJA USŁUGI DSR NA PRZYKŁADZIE DOMÓW JEDNORODZINNYCH
PublicationW artykule przedstawiono ideę usługi DSR, czyli reakcji strony popytowej, dla odbiorców rozproszonych. Polega ona na zmniejszeniu zapotrzebowania na energię elektryczną lub przesunięcia go w czasie. Wdrożenie usługi może w znaczny sposób wpłynąć na pracę systemu elektroenergetycznego – usługa DSR może wspomóc bilansowanie systemu elektroenergetycznego, a także pozytywnie oddziaływać na jego elastyczność, wydajność oraz stabilność....
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Rigid polyurethane foams with different flame retardants and their physical and mechanical properties
PublicationRigid polyurethane foams (PUFs) containing 3, 6 or 9 % of one of of two selected fire retardants (FR): oligomeric ethyl ethylene phosphate (Fyrol PNX) and expandable graphite (EG) were prepared, inspected and compared to foam without that fillers as the control. The thermal stability of PUFs was described by horizontal test according to norm: UL 94 HB. Compressive strength and physical properties (density, fragility and water absorption)...
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DiSTFAG method robust to gross errors in monitoring displacements and strains in unstable reference systems
PublicationThe DiSTFA method (Displacements and Strains using Transformation and Free Adjustment) was presented in Kamiński (2009). The method has been developed for the determination of displacements and strains of engineering objects in unstable reference systems, as well as for examining the stability of reference points. The DiSTFAG (Gross errors) method presented in the paper is the extension of the DiSTFA method making it robust to...
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Dynamics of a simplified HPT model in relation to 24h TSH profiles
PublicationWe propose a simplified mathematical model of the hypothalamus-pituitary-thyroid (HPT) axis in an endocrine system. The considered model is a modification of the model proposed by Mukhopadhyay and Bhattacharyya in [10]. Our system of delay differential equations reconstructs the HPT axis in relation to 24h profiles of human in physiological conditions. Homeostatic control of the thyroid-pituitary axis is considered by using...
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State Observer for Doubly-fed Induction Generator
PublicationIn the paper a new state observer for doubly-fed generator has been proposed. In the new approach an extended mathematical model of the doubly fed generator is used to form equations of the introduced z type observer. Stability of the observer has been verified through poles placement analyses. The active and reactive powers of the generator are controlled by a nonlinear multiscalar control method. Simulation and experimental results...
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Effects of La0.8Sr0.2MnO3 and Ag electrodes on bismuth-oxide-based low-temperature solid electrolyte oxygen generators
PublicationIn this study, La0.8Sr0.2MnO3 (LSM) was used as the ceramic electrode in a (Bi1.50Y0.50)0.98Zr0.04O3+δ (BYO)-based solid electrolyte oxygen generator (SEOG) and its performance was compared with that of a previously studied high-fire Ag electrode. Among La0.6Sr0.4Co0.2Fe0.8O3, LaNi0.6Fe0.4O3, Cu1.4Mn1.6O4, and LSM materials, only LSM materials did not trigger any chemical reaction or interdiffusion with BYO at temperatures up to...
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Self-organized multilayered graphene-boron doped diamond hybrid nanowalls for high performance electron emission devices
PublicationCarbon nanomaterials like nanotubes, nanoflakes/nanowalls and graphene have been used as electron sources due to their superior field electron emission (FEE) characteristics. Nevertheless, these materials show poor stability and a short lifetime, preventing them from being used in practical device applications. The intention of this study was to find an innovative nanomaterial, possessing both high robustness and reliable FEE behavior....
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Enzymatic and Chemical Cross-Linking of Bacterial Cellulose/Fish Collagen Composites—A Comparative Study
PublicationThis article compares the properties of bacterial cellulose/fish collagen composites (BC/Col) after enzymatic and chemical cross-linking. In our methodology, two transglutaminases are used for enzymatic cross-linking—one recommended for the meat and the other proposed for the fish industry—and pre-oxidated BC (oxBC) is used for chemical cross-linking. The structure of the obtained composites is characterized by scanning electron...
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Viability of fruit seed oil O/W emulsions in personal care products
PublicationThe use of fruit seed oils in personal care products is of significance to both their function and image. Poland is an important processor of fruit products within the EU, and thus has a large availability of seeds from domestic fruits, which are normally considered to be a waste material or feed for livestock. Unfortunately, current literature is scarce of the suitability of these oils for topical dermatological use in the form...
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Influence of silver-core gold-shell nanoparticle parameters on the variation of surface-enhanced Raman spectra
PublicationThe detection of molecules by surface-enhanced Raman spectroscopy (SERS) is dependent on the nanomaterial used to induce the enhancement effect. This depends on a variety of parameters of the substrate such as the metal used for their creation, their shape, size and size distribution, concentration, as well as the parameters of the solution, such as packing of the nanoparticles, the complexity of the sample, the solvent, etc. It...
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Investigation of Thermoplastic Polyurethanes Synthesized via Two Different Prepolymers
PublicationThe man aim of this work was to investigate the effect of the molecular weight of polyols, mixture of prepolymers, and [NCO]/[OH] molar ratio used during the prepolymer chain extending step on the chemical structure, thermomechanical and mechanical properties, and thermal stability of thermoplastic poly(ether-urethane)s In this work thermoplastic poly(ether-urethane)s were synthesized by using polyols with a various molecular weight,...
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Application of soil nailing technique for protection and preservation historical buildings
PublicationSoil nailing is one of the recent in situ techniques used for soil improvement and in stabilizing slopes. The process of soil nailing consists of reinforcing the natural ground with relatively small steel bars or metal rods, grouted in the pre-drilled holes. This method has a wide range of applications for stabilizing deep excavations and steep slopes. Soil nailing has recently become a very common method of slope stabilisation...
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Hyaluronan-Chondroitin Sulfate Anomalous Crosslinking Due to Temperature Changes
PublicationGlycosaminoglycans are a wide class of biopolymers showing great lubricating properties due to their structure and high affinity to water. Two of them, hyaluronic acid and chondroitin sulfate, play an important role in articular cartilage lubrication. In this work, we present results of the all-atom molecular dynamics simulations of both molecules placed in water-based solution. To mimic changes of the physiological conditions,...
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Theoretical study of thermofrictional oscillations due to negative friction-temperature characteristic
PublicationAnalytical study on oscillations of a body on a moving counterbody has been done by assuming imperfect frictional thermal contact and friction that decreases with contact temperature. It has been shown that stick-slip oscillation occurs due to decrease of friction coefficient when the body moves in the opposite direction to the counterbody. Dynamical characteristics, such as conditions for stable sliding and limit cycles, have...
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COMPUTER-AIDED DESIGN OF ORGANOPHOSPHORUS INHIBITORS OF UREASE
PublicationBased on the structure of the most potential inhibitor diamidophosphate, various novel groups of inhibitors were developed by knowledge-based design approach with covalent carbon-phosphorus or carbon-phosphorus-carbon bond to improve hydrolytic stability to inhibit the microbial ureases. Designed compounds were evaluated with 10 (LigScore1, LigScore2, PLP1, PLP2, JAIN, PMF, PMF04, LUDI_1, LUDI_2 and LUDI_3) different scoring functions...
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulationand evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modelingand solution rely on finite element methods and cover the simulation of the structure’s properties along with the influenceof the marine environment – sea currents, wave...
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The Issue of Shading Photovoltaic Installation Caused by Dust Accumulation on the Glass Surface
PublicationThe issue of accumulation of dust and other pollutants on the surface of photovoltaic modules was thoroughly analysed over the years. One of the first surveys in this field of knowledge linked pollutant accumulation on the module surface with transmittance loss of its glass covering, which leads to lessened amount of solar radiation reaching solar cells. First stage of this accumulation process is linear transparency loss, and second...
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Two-Row ESPAR Antenna with Simple Elevation and Azimuth Beam Switching
PublicationIn this letter, we propose a two-row electronically steerable parasitic array radiator (ESPAR) antenna designed for direction of arrival (DoA) estimation in Internet of Things (IoT) applications relying on simple microcontrollers. The antenna is capable of elevation and azimuth beam switching using a simple microcontroller-oriented steering circuit and provides 18 directional radiation patterns, which can be grouped in 3 distinctive...
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Society 4.0: Issues, Challenges, Approaches, and Enabling Technologies
PublicationThis guest edition of Cybernetics and Systems is a broadening continuation of our last year edition titled “Intelligence Augmentation and Amplification: Approaches, Tools, and Case Studies”. This time we cover research perspective extending towards what is known as Society 4.0. Bob de Vit brought the concept of Society 4.0 to life in his book “Society 4.0 – resolving eight key issues to build a citizens society”. From the Systems...
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Variations in host surfaces morphology and biology of ciliate epibionts explaining distribution pattern of epibionts in the invasive signal crayfish Pacifastacus leniusculus (Dana, 1852)
Publicationciliates on the signal crayfish Pacifastacus leniusculus in relation to specialized structures of the host’s exoskeleton for the first time. This species is known to maintain a relatively clean carapace, but it is sometimes overgrown by other organisms. Epibionts cover different parts of the signal crayfish body, mainly antennae, antennules, maxillipedes III and pereiopods with inner edges of chelae; however, some parts of the...
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A survey on network resiliency methodologies against weather-based disruptions
PublicationDue to the increasing dependence on network services of our society, research has recently been concentrating on enhancing traditional protection strategies to withstand large-scale failures, as in case of disaster events. The recently-formed EU-funded RECODIS project aims at coordinating and fostering research collaboration in Europe on disaster resiliency in communication networks. In particular, the Working Group (WG) 2 of the...
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Modelling of some stealth features for a small navy ship at the concept design stage.
PublicationIn this paper the basic research problems associated with modelling the basic stealth features for a small navy ship at the concept design stage are introduced. Amongst the major stealth features considered are: the modification of the immersed ship hull form by a rapid change of the ship loading condition, and modification of the ship boundary layer by the hull skin cover. The other stealth features of the ship are not presented...
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Heat recovery from the hybrid photovoltaic tile – experimental studies with the solar light simulator
PublicationConsidering the current development of micro-cogeneration energy sources, supported by the national prosumer policy and the act on the renewable energy sources, there is a great demand for the effective solar technologies. In this area, the photovoltaic cells with a combined conversion of the solar radiation energy into the electrical and thermal energy (PV/T cells) seem to be attractive. They are already widely available and treated...
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Decentralized Microgrid Energy Management System with Market-Based Energy Trade System
PublicationThis paper presents a decentralized energy management system for a power microgrid, which integrates individual users, who own renewable energy sources and energy storages. The purpose of the system is to make optimal use of available resources to cover the electricity needs of the whole microgrid. Thanks to the energy exchange system, in addition to exchanges with the distribution network, the system also allows trades within...
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Glaciers as an Important Element of the World Glacier Monitoring Implemented in Svalbard
PublicationGlaciers are not only contributors to the sea level rise but also important players in the circulation of pollutants. Over a billion people apply glacial waters for domestic purposes; hence, both the quality and quantity of this water should be monitored. In this chapter, we concentrate on the archipelago Svalbard in the Arctic, a typical target area for xenobiotics from long range atmospheric transport (LRAT), holding an important share...
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Wpływ imperfekcji geometrycznych na bezpieczeństwo montażu i naprawy zbiorników cylindrycznych metoda podbudowy
PublicationW pracy zajęto się wyznaczeniem nośności granicznej zbiorników stalowych o osi pionowej montowanych lub naprawianych z zastosowaniem hydraulicznego systemu podnoszenia konstrukcji. Podniesiony zbiornik jest szczególnie narażony na utratę stateczności, a obciążenie wiatrem utrudnia prowadzenie prac. Jakiekolwiek deformacje blach, szczególnie w pobliżu zamocowań podnośników mogą w znacznym stopniu obniżyć obciążenie krytyczne konstrukcji....
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The influence of external interference on AFM imaging, the use of a protective helmet
Open Research DataThis collection is of purely practical importance, showing how the presence of external disturbances can adversely affect the quality of imaging with an atomic force microscope. For this reason, it is also advisable to provide a link to a workshop-like study [1] as well as a huge number of commercial solutions available after entering the keyword "AFM...
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublicationNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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Weighted difference schemes for systems of quasilinear first order partial functional differential equations
PublicationThe paper deals with initial boundary value problems of the Dirichlet type for system of quasilinear functional differential equations. We investigate weighted difference methods for these problems. A complete convergence analysis of the considered difference methods is given. Nonlinear estimates of the Perron type with respect to functional variables for given functions are assumed. The proof of the stability of difference problems...
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Computer-aided analysis of resonance risk in power system with Static Var Compensators
PublicationStatic Var Compensators operation in a power system may significantly improve voltage profiles in nodes and the reactive power balance, as well as ensure greater system stability in emergency conditions. However these devices may be a cause of a resonance in the system. The aim of this paper is to call attention to the need to include resonance phenomena in a compensator’s location evaluation process. The analysis performed in...
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Synthesis and Testing of BCZY/LNZ Mixed Proton–electron Conducting Composites for Fuel Cell Applications
PublicationA composite of BaCe0.6Zr0.2Y0.2O3–δ and Li2O:NiO:ZnO was investigated for fuel cell applications. The composite was successfully synthesized and its phase stability was confirmed at temperatures up to 900 °C. The influence of sintering and pressing aids on density was also investigated. Electrical properties were measured. DC electrical conductivity was about 8•10-4 S/m at 845 K. Open circuit voltage measurements in wet hydrogen...
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ECONOMICAL AND SAFE METHOD OF GRANULAR MATERIAL STORAGE IN SILOS IN OFFSHORE PORT TERMINALS
PublicationThe article discusses issues related with storage of granular materials in silos made of corrugated sheets and reinforced with vertical ribs. Advantages and disadvantages of these structures are named, and typical technological solutions used by largest silo producers are presented. Moreover, basic assumptions of Eurocode 3 are discussed in the context of determining the buckling load capacity of a ribbed jacket. Alternative methods...
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Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublicationThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
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Analysis of a gene expression model
PublicationWe study a mathematical model of gene transcription and protein synthesis with negative feedback. We consider a system of equations taking into account the number of active binding sites, the way in which dimers bind to DNA and time delay in translation process. For a simplified model that consist of three ordinary differential equations with time delay we derive conditions for stability of the positive steady state and for the...