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Search results for: MOMENT-FITTING QUADRATURE
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Mechanical and structural investigations of wings of selected insect species
PublicationThis paper presents research and measurements leading to obtaining the Young’s modulus of wing bearing structures of selected insect species. A small testing machine intended for three-point bending and equipped with instruments registering low forces was constructed for the needs of the experiment. The machine was used to perform numerous bending tests of wings of three species of insects (obtained from a breeding farm): Attacus...
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Aerodynamic Shape Optimization for Delaying Dynamic Stall of Airfoils by Regression Kriging
PublicationThe phenomenon of dynamic stall produce adverse aerodynamic loading which can adversely affect the structural strength and life of aerodynamic systems. Aerodynamic shape optimization (ASO) provides an effective approach for delaying and mitigating dynamic stall characteristics without the addition of auxiliary system. ASO, however, requires multiple evaluations time-consuming computational fluid dynamics models. Metamodel-based...
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Diaryl Sulfide Derivatives as Potential Iron Corrosion Inhibitors: A Computational Study
PublicationThe present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the...
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Real-time hybrid model of a wind turbine with doubly fed induction generator
PublicationIn recent years renewable sources have been dominating power system. The share of wind power in energy production increases year by year, which meets the need to protect the environment. Possibility of conducting, not only computer simulation, but also laboratory studies of wind turbine operation and impact on the power system and other power devices in laboratory conditions would be very useful. This article presents a method...
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Cast Iron Staircase in Aleksandrów Kujawski (Poland) - History, Construction, Architectural Form
PublicationThe text presents historic cast iron staircase, which is situated inside the railway station building in Aleksandrów Kujawski. Since the moment of creation in the 19th century for a long time that station, located at the border of Prussia and Kingdom of Poland, was an important transit point. Nowadays it is situated in the central of Poland. The staircase was built in 1870’s as a result of an extension of the railway station building...
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Speed estimation of a car at impact with a W-beam guardrail using numerical simulations and machine learning
PublicationThis paper aimed at developing a new method of estimating the impact speed of a passenger car at the moment of a crash into a W-beam road safety barrier. The determination of such a speed based on the accident outcomes is demanding, because often there is no access to full accident data. However, accurate determination of the impact speed is one of the key elements in the reconstruction of road accidents. A machine learning algorithm...
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Noise Generated by Tyres Designet for Electric Vehicles - Results of Laboratory Experiments
PublicationA few years ago, electric and hybrid vehicles were rarely seen on public roads and were considered more as exotic curiosities or even as a sign of extravagance than a practical means of transport. Nowadays the situation has changes significantly. This was caused both by the technical development and legislative actions, as well as the organizational nature promoting the purchace and use of low emission vehicles. Electric vehicles...
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Dielectric Spectroscopy Studies and Modelling of Piezoelectric Properties of Multiferroic Ceramics
PublicationCompounds and solid solutions of bismuth ferrite (BiFeO3)—barium titanate (BaTiO3) system are of great scientific and engineering interest as multiferroic and potential high-temperature lead-free piezoelectric materials. In the present paper, the results of research on the synthesis and characterisation of 0.67Bi1.02FeO3–0.33BaTiO3 (67BFBT) ceramics in terms of crystal structure and dielectric and piezoelectric properties are reported....
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Fast Multi-Objective Aerodynamic Optimization Using Sequential Domain Patching and Multifidelity Models
PublicationExploration of design tradeoffs for aerodynamic surfaces requires solving of multi-objective optimization (MOO) problems. The major bottleneck here is the time-consuming evaluations of the computational fluid dynamics (CFD) model used to capture the nonlinear physics involved in designing aerodynamic surfaces. This, in conjunction with a large number of simulations necessary to yield a set of designs representing the best possible...
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Fragility analysis of structural pounding between adjacent structures arranged in series with various alignment configurations under near‑field earthquakes
PublicationA major cause of local to total damages is related to structural pounding in a large number of past earthquakes. In general, these collisions take place as a result of differences in the dynamic characteristics of the colliding structures. To acquire a better perception of the behavior of structures, in this paper, three structures featuring different heights are modeled in series and with various configurations next to each other...
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Probabilistic assessment of SMRFs with infill masonry walls incorporating nonlinear soil-structure interaction
PublicationInfill Masonry Walls (IMWs) are used in the perimeter of a building to separate the inner and outer space. IMWs may affect the lateral behavior of buildings, while they are different from those partition walls that separate two inner spaces. This study focused on the seismic vulnerability assessment of Steel Moment-Resisting Frames (SMRFs) assuming different placement of IMWs incorporating nonlinear Soil-Structure Interaction (SSI)....
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Seismic performance evaluation of steel buckling-restrained braced frames including SMA materials
PublicationThe permanent deformation of the building after seismic excitations can be determined by the Maximum Residual Interstory Drift Ratio (MR-IDR), which may be used for measuring the damage states. Low-post yield stiffness of the steel buckling-restrained braced frame (BRBF) makes this system vulnerable to large MR-IDR after a severe earthquake event. To overcome this issue, this paper investigates the seismic limit state performances...
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Performance of Vector-valued Intensity Measures for Estimating Residual Drift of Steel MRFs with Viscous Dampers
PublicationViscous Dampers (VDs) are widely used as passive energy dissipation system for improving seismic performance levels especially in retrofitting of buildings. Residual Inter-story Drift Ratio (R-IDR) is another important factor that specifies the condition of building after earthquake. The values of R-IDR illustrates the possibility of retrofitting and repairing of a building. Therefore, this study aims to explore the vector-valued...
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eFRADIR: An Enhanced FRAmework for DIsaster Resilience
PublicationThis paper focuses on how to increase the availability of a backbone network with minimal cost. In particular, the new framework focuses on resilience against natural disasters and is an evolution of the FRADIR/FRADIR-II framework. It targets three different directions, namely: network planning, failure modeling, and survivable routing. The steady state network planning is tackled by upgrading a sub-network (a set of links termed...
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Predicting the seismic collapse capacity of adjacent SMRFs retrofitted with fluid viscous dampers in pounding condition
PublicationSevere damages of adjacent structures due to structural pounding during earthquakes have emphasized the need to use some seismic retrofit strategy to enhance the structural performance. The purpose of this paper is to study the influence of using linear and nonlinear Fluid Viscous Dampers (FVDs) on the seismic collapse capacities of adjacent structures prone to pounding and proposing modification factors to modify the median...
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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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Biomechanics of Lumbar Spine Injury in Road Barrier Collision–Finite Element Study
PublicationLiterature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite...
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ENERGY ANALYSIS OF PROPULSION SHAFT FATIGUE PROCESS IN ROTATING MECHANICAL SYSTEM PART I TESTING SIGNIFICANCE OF INFLUENCE OF SHAFT MATERIAL FATIGUE EXCITATION PARAMETERS
PublicationThe article discusses the problem of mathematical modelling of energy conversion processes in a rotating mechanical system for the purpose of identifying fatigue states of propulsion shafts in this system. A simplified physical model of the analysed system, constructed in an appropriate scale, has made the basis for the experimental research. The research programme took into consideration mechanical fatigue excitation of the model...
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Unravelling the role of electron–hole pair spin in exciton dissociation in squaraine-based organic solar cells by magneto-photocurrent measurements
PublicationA high absorption coefficient and narrow absorption bands in squaraine (SQ) dyes have resulted in rapidly growing interest in them as a donor material in photovoltaic devices. The exciton dissociation process in organic systems proceeds via a multistep mechanism where the electron–hole pairs (charge transfer states) involved in the current generation process determine the recombination losses and subsequently limit the overall...
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The Handling of Business Lawsuits by Common Courts in Poland: Identification of Transaction Costs
PublicationCelem artykułu jest identyfikacja czynników mających wpływ na koszty transakcyjne dochodzenia praw z umów pomiędzy przedsiębiorcami w sprawach gospodarczych. Na potrzeby artykułu przeprowadzono pilotażowe badanie 210 spraw sądowych zawisłych przed Sądem Okręgowym w Gdańsku w pierwszej instancji po 2009 r., w których wyrok wydano w 2012 r. (ostatnie 210 spraw) a od wyroku wniesiono apelację do Sądu Apelacyjnego w Gdańsku i zakończono...
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Knowledge Exchange Between KIBS Firms and Their Clients: Case Study Analysis
PublicationPurpose: This paper aims to analyse knowledge exchange between KIBS firms and their clients, and their potential determinants (e.g. client’s education, type of the service offered, channel of the knowledge exchange, and willingness of the customer to accept the knowledge). The paper is based on a literature analysis and a case study research, examining 5 KIBS firms located in the Pomeranian region in Poland. Methodology: On the...
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Pharmaceuticals and another groups of emerging contaminants: Occurrence and sources in Admiralty Bay (King George Island, Maritime Antarctica)
PublicationEveryday live activities may introduce a wide range of chemicals into wastewater systems. In this study presence of selected types of pharmaceuticals from cardiovascular system group, nervous and muscolo-skeleton system group, antimicrobial agents, genitourinary and sex hormones were tested in the wastewater from H. Arctowski Antarctic station. Moreover, the receiver of discharged wastewater (Admiralty Bay) were also studied. Considering...
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Optical and photocatalytic properties of rare earth metal-modified ZnO quantum dots
PublicationA series of novel ZnO quantum dots modified with rare earth metals was successfully prepared by a simple sol-gel approach. The effects of types (Eu, Er, Tb, Yb, Ho, La) and amounts (from 0.09 to 0.45 mmol) of lanthanides on the optical properties, structural characterization and photocatalytic activity of ZnO/RE QDs were systematically investigated. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform...
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Charge Distribution and Hyperfine Interactions in GdBa2Cu3O7 from First Principles
PublicationW rozdziale przedstawiono wyniki obliczeń "z zasad pierwszych" (''ab initio'') struktury elektronowej, rozkładu ładunku i struktury nadsubtelnej, w szczególności gradientu pola elektrycznego (EFG) i składnika kontaktowego pola nadsubtelnego (HFF), nadprzewodnika wysokotemperaturowego o wzorze GdBa2Cu3O7 (Gd123). Do obliczeń wykorzystano metodę FP-LAPW (full-potential linearized augmented plane wave). Efekty związane z oddziaływaniami...
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Enhancing seismic performance of rigid and semi-rigid connections equipped with SMA bolts incorporating nonlinear soil-structure interaction
PublicationNowadays, using smart connections can improve the performance of buildings with some recentering features that are from the superelastic behavior of Shape Memory Alloys (SMAs). It seems that there is different rigidity between the designed connection and the real one in Steel Moment-Resisting Frames (SMRFs), which can be considered as a problematic issue due to the importance of connections in seismic performance assessment. This...
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Europe, between Mandatory and Voluntary Approach to CSR: Some New Evidence from the Polish Listed Companies
PublicationThis paper aims to explore the relationship between corporate governance rules and application of CSR practices into operations of the top 30 companies listed on the Warsaw Stock Exchange. Since in Poland, so far, there is no obligation to follow any specific CSR standards or to make disclosures of non-financial, social and environmental information, this is still a fully voluntary approach. At the moment, only some of the companies...
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Measurement Campaign and Mathematical Model Construction for the Ship Zodiak Magnetic Signature Reproduction
PublicationThe paper presents the partial work done within the framework of the EDA Siramis II project focused on magnetic signature reproduction of ships. Reproduction is understood here as the ability to determine the magnetic anomaly of the local Earth magnetic field in any direction and at any measurement depth due to the presence of the analysed object. The B-91 type hydrographic ship Zodiak was selected as the real case study. The work...
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Machine learning-based seismic response and performance assessment of reinforced concrete buildings
PublicationComplexity and unpredictability nature of earthquakes makes them unique external loads that there is no unique formula used for the prediction of seismic responses. Hence, this research aims to implement the most well-known Machine Learning (ML) methods in Python software to propose a prediction model for seismic response and performance assessment of Reinforced Concrete Moment-Resisting Frames (RC MRFs). To prepare 92,400 data...
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Yade-open DEM: an open-source software using a discrete element methodto simulate granular material
PublicationPurpose - YADE-OPEN DEM is an open source software based on the Discrete Element Method which uses object oriented programming techniques. The paper describes the softwarearchitecture.Design/methodology/approach - The DEM chosen uses position, orientation, velocity and angular velocity as independent variables of simulated particles which are subject to explicit leapfrog time-integration scheme (Lagrangian method). The three-dimensional...
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
PublicationThis paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark...
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Techniczne i ekonomiczne aspekty wykorzystania przekształtników dwukierunkowych w praktyce
PublicationNowoczesne napędy z silniami indukcyjnymi klatkowymi i przemiennikami częstotliwości stanowią blisko 90% napędów elektrycznych z regulowana prędkością kątową. Dzięki zastosowaniu nowych typów silników, przekładni oraz nowych generacji tranzystorów IGBT w przekształtnikach napędy te są energooszczędne, zaś koszt ich instalacji zwraca się średnio w ciągu kilkudziesięciu miesięcy od chwili zainstalowania. W 95% są to napędy z jednokierunkowym...
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Oddziaływanie przepięć łączeniowych na izolację kabli polietylenowych
PublicationDrzewienie elektryczne jest jedną z form degradacji izolacji w kablach elektroenergetycznych, szczególnie w końcowej fazie rozwoju, jako następstwo drzewienia wodnego. W związku z tym konieczne jest jego wykrywanie w celu poprawnej eksploatacji linii kablowych. Ważna jest przy tym znajomość mechanizmu powstawania i rozwoju w czasie wyładowań niezupełnych (wnz), która może wyznaczyć stan i tempo pogarszania izolacji. W pracy analizowano...
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Predicting seismic response of SMRFs founded on different soil types using machine learning techniques
PublicationPredicting the Maximum Interstory Drift Ratio (M-IDR) of Steel Moment-Resisting Frames (SMRFs) is a useful tool for designers to approximately evaluate the vulnerability of SMRFs. This study aims to explore supervised Machine Learning (ML) algorithms to build a surrogate prediction model for SMRFs to reduce the need for complex modeling. For this purpose, twenty well-known ML algorithms implemented in Python software are trained...
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Investigating an Optimal Computational Strategy to Retrofit Buildings with Implementing Viscous Dampers
PublicationCivil engineering structures may seriously suffer from different damage states re-sult of earthquakes. Nowadays, retrofitting the existing buildings is a serious need among designers. Two important factors of required performance level and cost of retrofitting play a crucial role in the retrofitting approach. In this study, a new optimal computational strategy to retrofit structures by implementing linear Viscous Dampers (VDs)...
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Optimal retrofit strategy using viscous dampers between adjacent RC and SMRFs prone to earthquake‑induced pounding
PublicationNowadays, retrofitting-damaged buildings is an important challenge for engineers. Finding the optimal placement of Viscous Dampers (VDs) between adjacent structures prone to earthquake-induced pounding can help designers to implement VDs with optimizing the cost of construction and achieving higher performance levels for both structures. In this research, the optimal placement of linear and nonlinear VDs between the 3-story, 5-story,...
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Governmental supported space internship programmes in new ESA member states - Polish perspective
PublicationOver last 10 years ve new countries - Czech Republic, Romania, Poland, Hungary and Estonia - have joined the European Space Agency. These countries are currently experiencing a considerable increase of space activities aiming to take part in the European and Global space market. New companies, start-ups and consortiums have been created alongside oces of foreign entities have opened their premises in these countries. All of them...
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Load effect impact on the exploitation of concrete machine foundations used in the gas and oil industry
PublicationMachine foundations is a critical topic in the gas and oil industry, which design and exploitation require extensive technical knowledge. Machine foundations are the constructions which are intended for mounting on it a specific type of machine. The foundation has to transfer dynamic and static load from machine to the ground. The primary difference between machine foundations and building foundations is that the machine foundations...
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Predicting sulfanilamide solubility in the binary mixtures using a reference solvent approach
PublicationBackground. Solubility is a fundamental physicochemical property of active pharmaceutical ingredients. The optimization of a dissolution medium aims not only to increase solubility and other aspects are to be included such as environmental impact, toxicity degree, availability, and costs. Obtaining comprehensive...
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Numerical analysis of lumbar spine injury during road safety barrier collision
PublicationPurpose: Enhancing road safety is a critical goal worldwide, necessitating the development of clear standards for road safety systems. This study focuses on lumbar spine (L-spine) compression injuries during collisions with concrete road safety barriers (RSBs). It aims to analyze internal forces during impact to understand L-spine injury biomechanics in such accidents. Methods: The research included a literature review, analyzing...
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Expedited constrained multi-objective aerodynamic shape optimization by means of physics-based surrogates
PublicationIn the paper, computationally efficient constrained multi-objective design optimization of transonic airfoil profiles is considered. Our methodology focuses on fixed-lift design aimed at finding the best possible trade-offs between the two objectives: minimization of the drag coefficient and maximization of the pitching moment. The algorithm presented here exploits the surrogate-based optimization principle, variable-fidelity computational...
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Microseismic Monitoring of Hydraulic Fracturing - Data Interpretation Methodology With an Example from Pomerania
PublicationMicroseismic monitoring is a method for localizing fractures induced by hydraulic fracturing in search for shell gas. The data is collected from an array of geophones deployed on the surface or underground. Ground vibrations are recorded and analysed for fracture location, magnitude and breakage mechanism. For successful microseismic monitoring one need a velocity model of underlying formations. The model is further tuned with...
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Mechanical strength of stems in aquatic macrophytes
PublicationSummary: In populations of submerged macrophytes, individuals are selected in terms of resistance to the effect of hydrodynamic forces. The aim of this study was to check whether individuals growing in river water are more tensile and bending resistant than plants occurring in places not exposed to flow stress. We determined the ultimate tensile strength of stems in four macrophyte species, Potamogeton natans, P. pectinatus, Batrachium...
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Study of Integer Spin S = 1 in the Polar Magnet β-Ni(IO3)2
PublicationPolar magnetic materials exhibiting appreciable asymmetric exchange interactions can potentially host new topological states of matter such as vortex-like spin textures; however, realizations have been mostly limited to half-integer spins due to rare numbers of integer spin systems with broken spatial inversion lattice symmetries. Here, we studied the structure and magnetic properties of the S = 1 integer spin polar magnet β-Ni(IO3)2...
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Smart Materials in Architecture: Useful Tools with Practical Applications or Fascinating Inventions for Experimental Design?
PublicationFor at least several decades smart or so-called intelligent materials, being the result of great advancements in material engineering, appear in architecture in different applications. Most of them are called "smart" because of their inherent properties: a real-time response to environmental stimuli. There are also those considered to be "smart" due to smart design: their original structure or the composition of their materials...
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Synteza bezczujnikowego sterowania maszyną indukcyjną klatkową zasilaną z falownika prądu
PublicationSynteza bezczujnikowego sterowania maszyną indukcyjną klatkową zasilaną z falownika prądu stanowi cel niniejszej monografii. Praca zawiera podstawowe informacje na temat modelowania układu napędowego z maszyną indukcyjną klatkową zasilaną z falownika prądu. Przedstawiono informacje na temat linearyzacji nieliniowych obiektów. Na pod-stawie metody syntezy strukturalnej opracowano nowe transformacje do postaci zmien-nych multiskalarnych,...
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Płyty przedprożowe z elewacji dawnego budynku jatek mięsnych w Gdańsku?
PublicationPodczas badań archeologicznych prowadzonych w latach 2004-2005 na terenie historycznych jatek mięsnych głównomiejskiego cechu rzeźników w Gdańsku, kierujący badaniami Robert Krzywdziński postawił tezę, że fragmenty płaskorzeźbionej dekoracji ściany szczytowej od strony ulicy Mariackiej, zniszczonego w 1945 roku budynku jatek, zostały wykorzystane jako elementy dekoracyjnych płyt przedprożowych podczas powojennej odbudowy kamienicy...
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Structural features responsible for control of the eukaryotic GlcN-6-P synthase activity
PublicationGlucosamine-6-phosphate (GlcN-6-P) synthase is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. As UDP-GlcNAc, the final product of the hexosamine path, constitutes one of the essential substrates for assembly of bacterial and fungal cell walls, the enzyme is an interesting target for antimicrobial therapy.The structure of E. coli enzyme, known since 2001, forms a dimer of two identical...
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Bezczujnikowe sterowanie maszynami elektrycznymi zasilanymi przekształtnikowo
PublicationOpracowanie teoretycznych podstaw do projektowania bezczujnikowych, nieliniowo sterowanych układów napędowych z maszynami elektrycznymi stanowiło zasadniczy cel monografii. Wiele zagadnień dotyczących bezczujnikowego sterowania zostało opracowanych dla modelu maszyny w postaci wektorowej. Autor niniejszej rozprawy zaproponował wykorzystanie modeli multiskalarnych do określenia zmiennych sterujących i nieliniowych sterowań odsprzęgających....
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Wpływ kryzysów i działań naprawczych na zaburzenia osobowości właściciela / menedżera MSP
PublicationZarządzanie przedsiębiorstwem znajdującym się w kryzysie jest ważnym tematem badawczym, gdyż przetrwanie jest podstawowym zadaniem każdego menedżera. Choć temat ten jest przedmiotem wielu badań, to autorzy nie podejmują zagadnienia wpływu kryzysu i działań naprawczych na stan psychiczny menedżera; zaburzenia osobowości są własnie tematem pracy. Celem pracy jest zaprezentowanie zebranego materiału empirycznego z sześciu przedsiębiorstw,...
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Algorytmy sterowania trakcją pojazdu autonomicznego z elektrycznymniezależnym napędem kół
PublicationW ostatnich latach rośnie zainteresowanie pojazdami autonomicznymi o napędzie elektrycznym lub hybrydowym. Na szczególną uwagę zasługują wielosilnikowe napędy, pozwalające dostosować moment na każdym kole pojazdu do warunków drogowych. Odpowiednie sterowanie momentem poszczególnych kół w każdej fazie ruchu pojazdu, zwłaszcza na krętej drodze oraz w warunkach niskiej, nierównomiernej i zmieniającej się w czasie przyczepności nawierzchni,...