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Search results for: BRIBES
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Environmental problems and health risks with disposable baby diapers: Monitoring of toxic compounds by application of analytical techniques and need of education
PublicationDue to the widespread use of disposable diapers in healthy babies as well as children prone to allergiesand premature babies with reduced immunity, disposable diapers should only be made of non-toxic andnatural ingredients. Unfortunately, disposable diaper manufacturers are reluctant to present their exactchemical composition, claiming that their trade secrets apply. However, several reports show thatdisposable diapers of well-known...
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Ukrainian Market of Electrical Energy: Reforming, Financing, Innovative Investment, Efficiency Analysis, and Audit
PublicationThe aim of this research is to determine the influence of electrical energy market regulation reform in Ukraine on the competitive environment, the reproduction processes of financial and innovative support, and the energy efficiency of the national economy. The authors have put forward and verified the hypothesis that, under conditions of institutional maturity of the Ukrainian electrical energy market, its liberalization and...
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PHYSICAL MODELLING OF GEOTECHNICAL STRUCTURES IN PORTS AND OFFSHORE
PublicationThe physical modelling of subsoil behaviour and soil-structure interaction is essential for the proper design of offshore structures and port infrastructure. A brief introduction to such modelling of geoengineering problems is presented and some methods and experimental devices are described. The relationships between modelling scales are given. Some examples of penetration testing results in centrifuge and calibration chamber...
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LCT, PIV and IR Imaging Detection in Selected Technical and Biomedical Applications
PublicationPaper presents the brief summary of the history of Thermochromic liquid crystals (TLC), Particle Image Velocimetry (PIV) and Infrared Imaging Themography (IR). Principal methods and tools are described and some examples are presented. With this objective, a new experimental technique have been developed and applied to the study of heat and mass transfer and for biomedical diagnosis. Selected results of experiments using these methods...
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Hybrid Approach in Project Management - Mixing Capability Maturity Model Integration with Agile Practices
PublicationThis paper introduces an idea of hybrid approach in managing software development projects. The main goal of this research is to prove that it is possible to design consistent method for managing software development projects which is based on different corporate standards and methods. Authors also want to show that this new hybrid approach is beneficial for IT organization, triggers synergy effects and brings software development...
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Numerical modelling and experimental verification of compressible squeeze film pressure
PublicationThe validity of using the Reynolds equation for compressible squeeze film pressure was tested with computational fluid dynamics (CFD). A squeeze film air bearing was instrumented with pressure sensors and non-contacting displacement probes to provide transient measurements of film thickness and pressure. The film thickness measurements also provided input parameters to the numerical prediction. However, numerical results showed...
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The impact of the overhead line's power supply system spatial differentiation on the energy consumption of trolleybus transport: planning and economic aspects
PublicationNowadays the issue of electric energy saving in public transport is becoming a key area of interest, which is connected both with a growth in environmental awareness of the society and an increase in the prices of fuel and electricity. It can be achieved by reducing of the transmission losses in supply system or by the improving of the usage of the regenerative breaking. The spatial differentiation of the energy supply system of...
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Niekorzystny wpływ przekształtnikowego zasilania PWM na silniki asynchroniczne trakcyjne
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...
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Destructive impact of PWM inverters on traction AC motors
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings's increased voltage exposure and...
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Destructive Consequences of PWM Inverter Feeding for Traction AC Motors
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...
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Numerical Characterization of Thresholds for the Focusing 1d Nonlinear Schrödinger Equation
PublicationThe focusing nonlinear Schrödinger equation arises in various physical phenomena and it is therefore of interest to determine mathematical conditions on the initial data that guarantee whether the corresponding solution will blow up in finite time or exist globally in time. We focus on solutions to the mass‐supercritical nonlinear Schrödinger equation (1) in 1D case. In particular, we investigate numerical thresholds between blow...
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Design criterion for hydrodynamic vortex separators
PublicationTechnical objects designing involves determination of geometrical parameters that characterize a given object. When the device is described by the differential equations, an inverse problem brings difficulties, as geometrical values sought condition the solution to the problem. Vortex separators can be designed by the "criterion method'. Firstly, a critical particle is distinguished such that bigger particles are removed from...
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Space-vector pulsewidth modulation for a seven-level cascaded H-bridge inverter with the control of DC-link voltages
PublicationThe control strategy of DC-link voltages for a seven-level Cascaded H-Bridge inverter is proposed in this paper. The DC-link voltage balancing is accomplished by appropriate selection of H-Bridges and control of their duty cycles in Space-Vector Modulation (SVM) algorithm. The proposed SVM method allows to maintain the same voltage level on all inverter capacitors. Regardless of the balancing function, the...
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Signal Processing in the Investigation of Two-phase Liquid-gas Flow by Gamma-ray Absorption
Publicationn this paper, the use of the gamma-absorption method applied in the investigation of the two-phase liquid-gas flow in the pipeline is described. An example of its application to the air transported by water in a horizontal pipeline is evaluated. In the measurements, Am-241 radioactive sources and probes with Nal (Tl) scintillation crystals have been used. The signals from the radiometric set were used to determine the velocity...
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Lung Protection by Cathepsin C Inhibition: A New Hope for COVID-19 and ARDS?
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Alternative Energy: Photovoltaic Solar Cells
PublicationSolar radiation is a fuel for photovoltaic cells and modules, which are a source of electric energy. Viable solar technologies that have been developed in the past are starting to be adopted on a broader and more meaningful global scale across different sectors with ever-increasing market penetration. In this entry, a brief overview of the material properties relevant to solar cell operation, the structure of the solar cell, and electrical...
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Krzysztof Łuksza mgr inż.
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Foreign Entry Modes of High-tech Firms in Poland
PublicationThe main objective of the article is to present the role and importance of foreign entry modes in internationalization process and their key determinants. Research methods: A quantitative research design was used. A survey was conducted on the sample of 263 firms operating in...
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Load capacity and serviceability conditions for footbridges made of fibre-reinforced polymer laminates = Warunki nośności i użytkowalności w odniesieniu do kładek z laminatów polimerowych
PublicationThe contribution is focused on derivation of the Ultimate Limit State (ULS) and Serviceability Limit State (SLS) design criteria for footbridges built of fibre-reinforced polymer matrix (FRP) laminates. The ULS design criterion is based on the design guidelines for above-ground, pressure, FRP composite tanks and the Tsai-Wu failure criterion, which is used to predict the onset of FRP laminates damage. The SLS criterion is based...
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Spękania niskotemperaturowe warstw asfaltowych nawierzchni
PublicationPraca ta stanowi przegląd dotychczasowych prac badawczych polskich i zagranicznych w zakresie odporności mieszanek mineralno-asfaltowych na spękania niskotemperaturowe. Autor przedstawił różne czynniki (materiałowe, środowiskowe, związane z konstrukcją nawierzchni i inne) wpływające na powstawanie spękań niskotemperaturowych. Omówiono rozkład temperatury na grubości warstw bitumicznych. Dokonano przeglądu laboratoryjnych metod...
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Symulacja hałasu pojazdów w trakcie manewrowania z małymi prędkościami - model CP2009
PublicationOgraniczenie halasu związanego z ruchem drogowym możliwe jest jedynie poprzez skoordynowane dzialanie w zakresie doskonalenia pojazdów, opon nawierzchni drogowych i organizacji ruchu drogowego. Praca porusza zagadnienia związane z manewrowaniem pojazdów na parkingach, stacjach paliw, terminalach promowych itp. Omówiono metodę prognozowania poziomu mocy akustycznej emitowanej z obiektu typu parking z uwzględnieniem charakterystyk...
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Podstawy określania współczynników równoważności obciążenia osi do projektowania nawierzchni drogowych
PublicationPraca przedstawia rys historyczny rozwoju charakterystyki obciążenia dróg przez ruch. Omówiono wpływ przyjęcia wielkości obciążenia standardowego osi równoważnej na wyniki analizy ruchu. Przedstawiono metodę doświadczalną AASHTO i współczynniki obliczone według tej metody w przypadku polskich warunków. Podano wzory do obliczeń współczynników dla osi podwójnych i potrójnych. Przedstawiono metodę francuską i jej porównanie z metodą...
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Kształtowanie nowych japońskich ''mostów wstęgowych''
PublicationNa przykładzie kilku ostatnio wybudowanych w Japonii ''mostów wstęgowych'', omówiono samą ideę, jej przeobrażenia oraz aktualne tendencje rozwojowe tego typu konstrukcji. Dowiązano do pewnych podobnych konstrukcji europejskich budowanych w przeszłości.
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Porównanie właściwości wybranych środków do stabilizacji gruntów na budowie autostrady A1
PublicationW pracy porównano właściwości spoiw występujących na polskim rynku. Przeprowadzono badania laboratoryjne gruntu z 8 spoiwami. Uzyskane właściwości gruntu stabilizowanego róznymi spoiwami porównywano ze stabilizacją cementem i wapnem. Najlepsze wyniki dla badanej gliny uzyskano przy stabilizacji cementem, co jest zaskakujące. Żadne spoiwo nie zapewniło wymaganej mrozoodporności.
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Badania terenowe przemieszczeniowych pali i kolumn wkręcanych typu SDP i SDC
PublicationPrzedstawiono opis badań pali i kolumn wkręcanych typu SDP i SDC na terenowym poletku doświadczalnym, wykonanych w ramach projektu badawczego MNiSW. Badania statyczne pali i kolumn wykonano z pomiarem rozdziału siły w trzonach i w powiązaniu z badaniami CPT podłoża gruntowego. Określono wartości oporów jednostkowych gruntów niespoistych wzdłuż pobocznicy i pod podstawą pali wkręcanych oraz przedstawiono je w relacji do oporów gruntu...
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Budowa i kalibracja modeli spękań zmęczeniowych warstw asfaltowych nawierzchni drogowych w mechanistyczno-empirycznej metodzie AASHTO 2004
PublicationW artykule przedstawiono sposób tworzenia modeli spękań zmęczeniowych warstw asfaltowych w nowej amerykańskiej mechanistyczno-empirycznej metodzie projektowania nawierzchni AASHTO 2004. Opisano modele przyjęte do kalibracji, problem różnego zachowania się warstw asfaltowych naprężeniowo i odkształceniowo,przyjęte miary spękań zmęczeniowych. Przedstawiono także kalibrację opartą o badania na odcinkach doświadczalnych LTPP, symulację...
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Właściwości betonu impregnowanego kompozycjami epoksydowymi
PublicationZabezpieczając powierzchnię betonu przez impregnację w obiektach drogowych i mostowych, można w znacznym stopniu ograniczyć proces przenikania gazów i cieczy, a tym samym zapobiegać destrukcji. Przedmiotem opracowania jest wpływ własności materiałów impregnacyjnych na właściwości i trwałość betonu. Szczególną uwagę w przeprowadzonych badaniach skierowano na skład kompozycji żywicznych. Sporządzono 160 impregnatów, spośród których...
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Wpływ różnych cięgien na właściwości statyczne i dynamiczne kładki podwieszonej
PublicationPrzedstawiono analizę wpływu rodzaju cięgna na cechy statyczne i dynamiczne konstrukcji podwieszonej kładki dla pieszych. Rozważano pręty lite, liny zwite i sploty 7*č5.
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ANALIZA WYBRANYCH CECH MECHANICZNYCH MIESZANEK MINERALNO-CEMENTOWO-EMULSYJNYCH (MCE)
PublicationW ostatnich latach mieszanki mineralno-cementowo-emulsyjne (MCE) stają się materia³em coraz częściej wykorzystywanym przy projektowaniu remontów i przebudów nawierzchni z wykorzystaniem recyklingu. Materiał ten zyskuje coraz większą popularność, ponieważ pozwala w sposób racjonalny i bez uszczerbku dla środowiska naturalnego ponownie wykorzystać materiały pochodzące z rozbiórki starych nawierzchni bitumicznych, w tym również materiały...
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ANALYSIS OF CLIMATIC ZONES IN POLAND WITH REGARD TO ASPHALT PERFORMANCE GRADING
PublicationTowards the end of the last century a new system of bitumen grading was developed and implemented as part of the American Strategic Highway Research Program (SHRP). Its aim was to better adjust the testing methods and requirements for road bitumens to the actual conditions in which those bitumens serve in road pavements. Currently in Poland, similarly as in the other EU countries, road bitumens are tested and classified with regard...
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Analiza trwałości zmęczeniowej asfaltów drogowych i modyfikowanych z wykorzystaniem testu liniowego zwiększania amplitudy / Analysis of the fatigue life of neat and modified bitumens using linear amplitude sweep test
PublicationThe paper presents an evaluation of the fatigue resistance of selected Polish bituminous binders: neat bitumen 50/70, polymer modified bitumen PMB 45/80-55 and polymer highly modified bitumen PMB 45/80-80. The linear amplitude sweep (LAS) test, which is a new bitumen performance grading test developed in the USA, and was used to assess the fatigue life of the bitumens. Highly modified bitumen 45/80-80 showed 10-20 times higher...
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Dynamic analysis of the railway bridge span under moving loads
PublicationThe first part of this paper provides a review of the state of knowledge of the dynamic behaviour of railway bridges under moving loads. Particular attention is paid to developments in modelling railway bridge loading and dynamic vehicle-span (structure) interaction. The most important aspects determining the advancements in this area of knowledge are identified. The contemporary techniques for defining bridge span finite element...
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Impact of reclaimed asphalt pavement (RAP) on low-temperature properties of asphalt concrete
PublicationHot mix recycling is a practice which enables reusing materials from old asphalt pavements. Current Polish regulations allow usage of RAP only for binder and base courses, and its amount is limited. Asphalt mixtures with RAP material have to fulfil requirements stated for typical asphalt mixtures. The research presents low-temperature properties of twelve different asphalt concretes with RAP material, determined using three-point...
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Application and evaluation of M-EPDG for performance analysis of Polish typical flexible and rigid pavements
PublicationThe main goal of the paper is to implement and evaluate the M-EPDG and the software AASHTOware to analyse the performance of new flexible and rigid pavements designed according to the Polish catalogues, which are comparable with analogous catalogues used in other European countries. For this purpose the site-specific inputs for Poland were determined and described in the paper as well as compared to the default input data used...
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Comprehensive two-dimensional gas chromatography - promising technique for analysis of complex food matrices
PublicationThe present paper is focused on brief description of operational principle of comprehensive two-dimensional gas chromatography (GC×GC) technique, instrumentation and data processing. Furthermore, the examples of application in the field of food analysis, performed also in the author's laboratory, are given. The detailed discussion of GC×GC characterization and comparison of the volatile composition of berries of different blue...
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Application of MARKAL model to optimisation of electricity generation structure in Poland in the long-term time horizon Part I - concept of the model
PublicationIn this paper, which inaugurates a series of papers on this subject, a concept is proposed of a power system development model with regard to the technological structure of electricity generation in Poland, in the long-term time perspective – until 2060. The model is based on the mathematical structure of the MARKAL optimization package. The paper presents a brief description of the tool used in the model research. In addition,...
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Challenges associated with the design of a small unmanned autonomous maritime vehicle
PublicationThe paper contains the preliminary results of the research connected with development of a small unmanned autonomous maritime vehicle. First of all a general description of research is introduced. Next, a concept of a vehicle is presented. Then, a brief description of a research method is given. Next, the current research problems under way are introduced. They concern the ballasting, motion and precise position stabilization system...
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Janusz Nieznański prof. dr hab. inż.
PeopleJanusz Nieznański born in 1957 in Gdańsk. He received the M.Sc. degree in 1981, the Ph.D. degree in 1990, and the D.Sc. (‘habilitation’) degree in 1999, all from the Gdańsk University of Technology. Since 1981 he has been with the above university, where he is currently Professor of Electrical Engineering. His research and teaching interests include control, diagnostics, modeling and simulation of power electronic converters and...
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Implementation of the Boundary Element Method to Two-Dimensional Heat Transfer with Thermal Bridge Effects
PublicationThe work presents an application of the boundary element method applied to a two-dimensional conductive heat transfer. The algorithm of the method is explained and its advantages are outlined. Green's function as a fundamental solution for Poisson's equation in two dimensions was used and the direct approach was applied. The presented results concern building construction elements as typical cases of thermal bridges. Some properties...
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Induction machine behavioral modeling for prediction of EMI propagation.
PublicationThis paper presents the results of wideband behavioral modeling of an induction machine (IM). The proposed solution enables modeling the IM differential- and common-mode impedance for a frequency range from 1 kHz to 10 MHz. Methods of parameter extraction are derived from the measured IM impedances. The developed models of 1.5 kW and 7.5 kW induction machines are designed using the Saber Sketch scheme editor and simulated in the...
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Annihilation rates of low-energy positron scattering from simple diatomic molecules
PublicationWe discuss the calculations of Zeff coefficients for a series of diatomic molecules over the range of energies below the positronium formation. During the development of a general code for polyatomic, nonlinear molecules colliding with positrons, it was discovered that the earlier one, employed only for diatomic molecules, had an error. The error is corrected and the corrected results are presented here. We also discuss a way of...
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Forecasted climate changes and their influence on cities and regions in 2050 in terms of extreme hydrological events
PublicationGlobal climate change is a problem which arises numerous theories and uncertainties, especially in terms of speculated human impact. Independent from the fact, what is the main driver for the changes, some of the climate shifts are visible already nowadays. Both contemporary and future cities will have to face such problems. Although climate change may cause numerous effects on different fields, a special stress in this article...
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Minimal surfaces and conservation laws for bidimensional structures
PublicationWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...
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Graphene hydrogels with embedded metal nanopatricles as efficient catalysts in 4-nitrophenol reduction and methylene blue decolorization
PublicationSynthesis and characterization of the graphene hydrogels with three different metallic nanoparticles, that is Au, Ag and Cu, respectively is presented. Synthesized in a one-pot approach graphene hydrogels with embedded metallic nanoparticles were tested as heterogeneous catalysts in a model reaction of 4-nitrophenol reduction. The highest activity was obtained for graphene hydrogel with Cu NPs and additional reaction of methylene...
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Analysis of different tillage implements with respect to reduced fuel consumption, tractor operating speed and its wheel slippage
PublicationNowadays the prices of agricultural farm produced products are increasing with ant-speed and the prices of input for raising crops are increasing with rocket-speed. Therefore, there is a dire need to conduct some important studies to innovate the techniques which can lower the costs of crop production. In this context, this study was conducted to evaluate the consumption of fuel at different tillage implements, tractor operating...
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Financial Consequences of the Introduction of the Fit For 55 on the Example of Poland
PublicationIn Europe and in Poland, there is a growing conviction that climate action is a necessity. When creating long-term strategies or making current decisions, companies are increasingly taking into account issues related to sustainable development and reducing CO2 emissions. Following the signing of the Paris Agreement in 2015, countries around the world pledged to reduce greenhouse gas emissions by 2050 so that the average temperature...
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Znaczenie monopolizacji w postkeynesowskich teoriach cenotwórstwa
PublicationArtykuł jest teoretyczną podstawą empirycznych analiz cen prowadzonych zgodnie z ekonomią postkeynesowską. Postkeynesiści, ze względu na krytyczny realizm jako metodologiczną podstawę ekonomii postkeynesowskiej, wyróżniają trzy teorie ustalania ceny przez przedsiębiorstwa – ceny administrowane (administered proces), cenotwórstwo oparte na kosztach normalnych (normal cost prices) i cenotwórstwo oparte na narzucie (mark up prices)....
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Synthesis, Chemical Characterization and Multiscale Biological Evaluation of a dimericcRGD Peptide for Targeted Imaging of αVβ3 Integrin Activity
PublicationCyclic peptides containing the Arg-Gly-Asp (RGD) sequence have been shown to specifically bind the angiogenesis biomarker α V β3 integrin. We report the synthesis, chemical characterization, and biological evaluation of two novel dimeric cyclic RGD-based molecular probes for the targeted imaging of α V β3 activity (a radiolabeled version, 64Cu-NOTA-PEG4-cRGD2, for PET imaging, and a fluorescent version, FITC-PEG4-cRGD2, for in...
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ZAAWANSOWANE SYMULACJE NUMERYCZNE MES DYNAMIKI MOSTÓW Z WYKORZYSTANIEM PROCEDURY EXPLICITE
PublicationDostęp do mocy obliczeniowej superkomputerów oraz możliwość wykorzystania nowoczesnych systemów, np. takich jak Ls-Dyna, pozwala na uzyskanie niezwykle szczegółowych rozwiązań bardzo skomplikowanych problemów inżynierskich. Zagadnienia te dotyczą zakresu statyki/stateczności jak i dynamiki dla rozbudowanych układów konstrukcyjnych zarówno w zakresie nieliniowości materiałowej jak i geometrycznej. Uzyskanie wiarygodnych wyników...
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Magnetic field maps of an astable multivibrator in frequency range from 30 MHz to 3 GHz – spatial detection
Open Research DataThe data presents a result of near field measurements of electromagnetic emissions radiated from the PCB of a small electronic device. An efficient method of modelling the magnetic and electric field emissions is the measurements in the near field using electric and magnetic probes. The attached files contain magnetic field maps created on based measurements...