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The In-House Method of Manufacturing a Low-Cost Heat Pipe with Specified Thermophysical Properties and Geometry
PublikacjaVarious types of heat pipes are available to purchase off the shelf, from various manufacturers, but most of them have strictly defined geometry and technical parameters. However, when there is a need to use a heat pipe (HP) with an unusual size and shape or working conditions other than the standard ones, it becomes very costly to order them from manufacturers, especially in small quantities, and only a few producers are willing...
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Newton’s Method for the McKendrick-von Foerster Equation
PublikacjaIn the paper we study an age-structured model which describes the dynamics of one population with growth, reproduction and mortality rates. We apply Newton’smethod to the McKendrick-von Foerster equation in the semigroup setting. We prove its first- and second-order convergence.
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Accurate Lightweight Calibration Methods for Mobile Low-Cost Particulate Matter Sensors
PublikacjaMonitoring air pollution is a critical step towards improving public health, particularly when it comes to identifying the primary air pollutants that can have an impact on human health. Among these pollutants, particulate matter (PM) with a diameter of up to 2.5 μ m (or PM2.5) is of particular concern, making it important to continuously and accurately monitor pollution related to PM. The emergence of mobile low-cost PM sensors...
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Wpływ budowy stopni wejściowych falowników na generowanie prądów wirowych i upływowych
PublikacjaPodstawowymi rozwiązaniami stopni wejściowych falowników są układy z:-prostownikiem 6-pulsowym stosowanym dla obniżenia kosztów,-prostownikiem 12 lub 18-pulsowym stosowanym dla obniżenia zniekształceń harmonicznych,- sterowanym prostownikiem 6-pulsowym PWM stosowanym dla obniżenia zniekształceń harmonicznych oraz zwiększenia współczynnika mocy.Zawartość harmonicznych po stronie zasilania ma wpływ na możliwość powstania potencjalnych...
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The effect of pre-hydrogen charging on corrosion behaviour of superduplex stainless steel welded joints
PublikacjaThe paper presents results of research undertaken to determine the influence of hydrogen on passivity and corrosion resistance of 2507 super duplex stainless steel welded joints. Butt welded joints were made with low heat input using flux corded arc welding (FCAW) method. Coupons of 5.0 x 5.0 mm were cut from the welded joints containing weld metal (WM), heat affected zone (HAZ) and parent metal (PM). Hydrogen was introduced...
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Automated detection of sleep apnea and hypopnea events based on robust airflow envelope tracking
PublikacjaThe paper presents a new approach to detection of apnea/hypopnea events, in the presence of artifacts and breathing irregularities, from a single-channel airflow record. The proposed algorithm identifies segments of signal affected by a high amplitude modulation corresponding to apnea/hypopnea events. It is shown that a robust airflow envelope—free of breathing artifacts—improves effectiveness of the diagnostic process and allows...
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A Quasi-2D MOSFET Model — 2D-to-Quasi-2D Transformation
PublikacjaA quasi-two-dimensional (quasi-2D) representation of the MOSFET channel is proposed in this work. The representation lays the foundations for a quasi 2D MOSFET model. The quasi 2D model is a result of a 2D into quasi 2D transformation. The basis for the transformation are an analysis of a current density vector field and such phenomena as Gradual Channel Detachment Effect (GCDE), Channel Thickness Modulation Effect (CTME), and...
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Toward Human Chromosome Knowledge Engine
PublikacjaHuman chromosomes carry genetic information about our life. Chromosome classification is crucial for karyotype analysis. Existing chromosome classification methods do not take into account reasoning, such as: analyzing the relationship between variables, modeling uncertainty, and performing causal reasoning. In this paper, we introduce a knowledge engine for reasoning-based human chromosome classification that stores knowledge...
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Model zużycia głównych podzespołów zespołu korbowo-tłokowego i rozrządu
PublikacjaW referacie na podstawie uszkodzeń zespołu korbowo-tłokowego i rozrządu silników Sulzer RD pobranych z syntetycznych danych o niezawodności wyposażenia wybranych statków PLO i PŻM zbudowany został model zużycia głównych podzespołów zespołu korbowo-tłokowego i rozrządu.
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Diagnostyka ogniw paliwowych
PublikacjaRosnące zapotrzebowanie na zieloną energię elektryczną, ograniczenia związane z normami emisji spalin, większa świadomość ekologiczna społeczeństwa, czy rozwój dolin wodorowych determinują fakt, że ogniwa paliwowe typu PEM będą stanowić ważne źródło energii elektrycznej w niedalekiej przyszłości.
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Phase Change Thermal Energy Storage – The Experience of the Materials Preparation for the Specific Applications.
PublikacjaThermal energy storage and temperature stabilization is very important in many engineering applications. There are three kinds of thermal energy storage: sensible heat storage, latent heat storage and reversible chemical reaction heat storage. Phase change materials (PCM) absorb, store and release large amounts of energy in the form of latent heat, at constant temperature, called the transition temperature. The amount of heat...
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Shallow Water Experiment of OFDM Underwater Acoustic Communications
PublikacjaThe large variability of communication properties of underwater acoustic channels, and especially the strongly varying instantaneous conditions in shallow waters, is a challenge for the designers of underwater acoustic communication (UAC) systems. The use of phase modulated signals does not allow reliable data transmission through such a tough communication channel. However, orthogonal frequency-division multiplexing (OFDM), being...
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Comprehensive two dimensional gas chromatography coupled with mass spectrometry as tool for characterization of the main pollutants present in atmospheric air in Gdansk
PublikacjaNowadays, the technique that is commonly used to identify and quantify the chemical compounds in gas sample is gas chromatography. The separation resolution in gas chromatography can be improved by applying the modulation technique. In this paper present is the most important information regarding the pollutants present in atmospheric air. The areas in which the tests were carried out are one of the largest industrial zones in...
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Correlated Particle Motion and THz Spectral Response of Supercritical Water
PublikacjaMolecular dynamics simulations of supercritical water reveal distinctly different distance-dependent modulations of dipolar response and correlations in particle motion compared to ambient conditions. The strongly perturbed H-bond network of water at supercritical conditions allows for considerable translationaland rotational freedom of individual molecules. These changes give rise to substantially different infrared spectra and...
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Molecular level interpretation of excess infrared spectroscopy
PublikacjaInfrared (IR) spectroscopy is an invaluable tool in studying intermolecular interactions in solvent mixtures. The deviation of the IR spectrum of a mixture from the spectra of its pure components is a sensitive measure of the non-ideality of solutions and the modulation of intermolecular interactions introduced by mutual influence of the components. Excess IR spectroscopy, based on the established notion of excess thermodynamic...
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A Novel Method for Intelligibility Assessment of Nonlinearly Processed Speech in Spaces Characterized by Long Reverberation Times
PublikacjaObjective assessment of speech intelligibility is a complex task that requires taking into account a number of factors such as different perception of each speech sub-bands by the human hearing sense or different physical properties of each frequency band of a speech signal. Currently, the state-of-the-art method used for assessing the quality of speech transmission is the speech transmission index (STI). It is a standardized way...
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Implementation of Haar wavelet, higher order Haar wavelet, and differential quadrature methods on buckling response of strain gradient nonlocal beam embedded in an elastic medium
PublikacjaThe present investigation is focused on the buckling behavior of strain gradient nonlocal beam embedded in Winkler elastic foundation. The first-order strain gradient model has been combined with the Euler–Bernoulli beam theory to formulate the proposed model using Hamilton’s principle. Three numerically efficient methods, namely Haar wavelet method (HWM), higher order Haar wavelet method (HOHWM), and differential quadrature method...
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Theoretical calculation of pKas of phosphoric (V) acidin the polarisable continuum and cluster-continuum models
PublikacjaW pracy oceniono dokładność modelu polaryzowalnego kontinuum (PCM) i mieszanego modelu klaster-kontinuum do przewidywania wartości trzech kolejnych stałych dysocjacji kwasu fosforowego (V). Obliczenia PCM na poziomie MP2/6-31+G(d,p) odtwarzają wartość pierwszego pKa z rozsądną niepewnością, jednak wartości kolejnych pKa obarczone są bardzo dużym błędem, nawet po podniesieniu poziomu teorii do metody zespolonej G3B3. Dopiero obliczenia...
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IDENTIFICATION OF ODOR OF VOLATILE ORGANIC COMPOUNDS USING CLASSICAL SENSORY ANALYSIS AND ELECTRONIC NOSE TECHNIQUE
PublikacjaThe paper compares two methods of analysis of odour of volatile organic compounds: classical sensory analysis and electronic nose technique. Eight volunteers participated in the classical sensory analysis investigations, which lasted two weeks. An instrumental odour analysis involved a prototype of 6-sensor electronic nose designed by the authors. The research performed with this device provided higher reproducibility and reliability...
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Comparison of state feedback and PID control of pressurizer water level in nuclear power plant
PublikacjaThe pressurizer water level control system in nuclear power plant with pressurized water reactor (PWR) is responsible for coolant mass balance. The main control goal is to stabilize the water level at a reference value and to suppress the effect of time-varying disturbances (e.g. coolant leakage in primary circuit pipeline system). In the process of PWR power plant operation incorrect water level may disturb pressure control or...
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Sustainable urban planning in the context of studentification of the inner city areas
PublikacjaThe social dimension of urban planning as well as the importance of local communities and civic participation are often underlined in contemporary urban renewal and revitalisation programmes based on the principles of sustainable development. British Urban Renaissance is one the most far-reaching and widely discussed urban regeneration strategies which aims at repopulation and social diversification of inner city areas and land...
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Rola ośrodków naukowych w regionalnym systemie innowacji
PublikacjaW artykule przedstawiono rolę uczelni wyższych w regionalnym systemie innowacji, na przykładzie Politechniki Warszawskiej. Artykuł zawiera wyniki badań dotyczących współpracy PW z przedsiębiorstwami high-tech na Mazowszu, opis działań podejmowanych przez władze PW, ukierunkowanych na intensyfikację współpracy z przemysłem jak również zaangażowanie PW w budowanie Regionalnej Strategii Innowacji dla Mazowsza.
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A new assay for simultaneous identification and differentiation of Klebsiella oxytoca strains
PublikacjaBacterial strain typing, or identifying bacteria at the strain level, is particularly important for diagnosis, treatment, and epidemiological surveillance of bacterial infections. This is especially the case for bacteria exhibiting high levels of antibiotic resistance or virulence, and those involved in nosocomial or pandemic infections. Strain typing also has applications in studying bacterial population dynamics.
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An assessment of health status and health behaviours in adolescents: main points and methods of the SOPKARD-Junior programme.
PublikacjaThe study involved preparing and implementing a model of screening assessments for adolescents and comparison of anthropometric examinations between the population of the SOPKARD-Junior programme and representative sample of Polish children in the same years.Additionally, data concerning attendance rates for particular examinations carried out under SOPKARD-Junior programme were presented.Revier2,comment 1
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Rozwój mediów i systemów transmisyjnych.
PublikacjaPrzedstawiono rys historyczny rozwoju przewodowych technik transmisji sygnałów. Omówiono media transmisyjne: kable symetryczne i współosiowe o przewodach miedzianych oraz kable optotelekomunikacyjne ze światłowodami. Scharakteryzowano techniki transmisyjne: wielokrotne systemy analogowe FDM oraz systemy cyfrowe PCM, PDH i SDH oraz ATM.
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New Method of Non-Linear Electrochemical Impedance Spectroscopy with an Amplitude-Modulated Perturbation Signal
PublikacjaThe paper presents a new method of non-linear electrochemical impedance spectroscopy (NLEIS), which allows fast and nondestructive evaluation of the corrosion rate and determination of the Tafel coefficients values for a corrosion system under investigation. This method employs amplitude modulation of the ac perturbation signal. The study demonstrated that it was possible to obtain impedance characteristic as a function of the...
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Actions of a nitric oxide donor on prostaglandin production and angiogenic activity in the equine endometrium
PublikacjaNitric oxide (NO) plays an important role in prostaglandin secretion and angiogenesis in the reproductive system. In the present study, the roles of the NO donor spermine NONOate and tumour necrosis factor-alpha (TNF; as a positive control) in prostaglandin production and angiogenic activity of equine endometria during the oestrous cycle were evaluated. In addition, the correlation between NO production...
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Multidisciplinary approach to the component design of a new axial hydraulic pump
PublikacjaArtykuł przedstawia rezultaty analizy przebiegów zmian ciśnienia w komorze cylindrowej pompy typu PWK o zmiennej wydajności. Ze względu na skomplikowane zjawiska i wzajemne interakcje między nimi zbudowano model pozwalający na połączenie analizy MES i CFD. Uzyskane wyniki porównano z wynikami eksperymentu.
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Application of normal-phase high-performance liquid chromatography followed by gas chromatography for analytics of diesel fuel additives
PublikacjaThe paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive...
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Research on the separation properties of empty-column gas chromatography (EC-GC) and conditions for simulated distillation (SIMDIS)
PublikacjaThe paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive...
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Electrochemical oxidation of landfill leachate using boron-doped diamond anodes: pollution degradation rate, energy efficiency and toxicity assessment
PublikacjaElectrochemical oxidation (EO), due to high efficiency and small carbon footprint, is regarded as an attractive option for on-site treatment of highly contaminated wastewater. This work shows the effectiveness of EO using three boron-doped diamond electrodes (BDDs) in sustainable management of landfill leachate (LL). The effect of the applied current density (25–100 mA cm−2) and boron doping concentration (B/C ratio: 500 ppm, 10,000...
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Selective transport of Pb(II) across polymer inclusion membrane using imidazole azocrown ethers as carriers.
PublikacjaZbadano selektywność transportu jonów ołowiu(II) z równomolowych roztworów jonów Zn(II), Cd(II) i Pb(II) przez polimerowe membrany inkluzyjne (PIM) zawierające imidazolowe etery azokoronowe.Wykazano, że polimerowe membrany inkluzyjne z imidazolowymi azokoronami wykazują dużą stabilność, zależną w dużym stopniu od rodzaju jonoforu.
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Hydrostatically discharged commutation unit and it's impact on axial pump's performance
PublikacjaW pracy przedstawiono wyniki analizy teoretycznej funkcjonowania rozrządu czołowego i hydrostatycznie odciążonego rozrządu krzywkowego w pompach wielotłoczkowych osiowych. Zaprezentowano także wyniki porównawczych badań sprawności mechaniczno-ciśnieniowej, objętościowej i całkowitej dla pomp o różnej konstrukcji. Podano informacje o produkowanych obecnie pompach typu PWK.
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Modelling of dark fermentation of glucose and sour cabbage
PublikacjaIn the article, modified Anaerobic Digestion Models 1 (ADM-1) was tested for modelling dark fermentation for hydrogen production. The model refitting was done with the Euler method. The new model was based on sets of differential equations. The model was checked for hydrogen production from sour cabbage in batch and semi-batch in 5 g VSS (volatile solid suspension)/L and at the semi-batch process from glucose at 5 and 10 g VSS/L....
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Arterial cannula shape optimization by means of the rotational firefly algorithm
PublikacjaThe article presents global optimization results of arterial cannula shapes by means of the newly modified firefly algorithm. The search for the optimal arterial cannula shape is necessary in order to minimize losses and prepare the flow that leaves the circulatory support system of a ventricle (i.e. blood pump) before it reaches the heart. A modification of the standard firefly algorithm, the so-called rotational firefly algorithm,...
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Multimodal Particle Swarm Optimization with Phase Analysis to Solve Complex Equations of Electromagnetic Analysis
PublikacjaIn this paper, a new meta-heuristic method of finding roots and poles of a complex function of a complex variable is presented. The algorithm combines an efficient space exploration provided by the particle swarm optimization (PSO) and the classification of root and pole occurrences based on the phase analysis of the complex function. The method initially generates two uniformly distributed populations of particles on the complex...
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The Employment of Ukrainians as an Opportunity to Fill the Labour Market in Poland – Selected Issues
PublikacjaThe labour market in Poland has undergone signifi cant transformations over the past two decades. The observed changes have been infl uenced by various factors related to, among other things, the possibility of free movement of the population resulting from membership of EU structures, demographic changes, technological changes, and the automation and robotisation of production processes. Demographic change is becoming a signifi...
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Application of thin diamond films in low-coherence fiber-optic Fabry Pérot displacement sensor
PublikacjaThe novel fiber-optic low coherence sensor with thin diamond films is demonstrated. The undoped and boron-doped diamond films were elaborated by the use of the microwave plasma enhanced chemical vapor deposition (μPE CVD) system. The optical signal from the Fabry–Pérot cavity made with the application of those thin films is sensitive to displacement. The sensor characterization was made in the range of 0–600 μm. The measurements...
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Hazardous gases detection by fluctuation-enhanced gas sensing
PublikacjaW pracy przedstawiono układ pomiarowy oraz metodę za pomocą której można jednym rezystancyjnym czujnikiem gazów wykrywać dwa gazy: amoniak i siarkowodór. Podano wskaźnik jaki pozwala dokonać detekcji tych gazów już przy stężeniach rzędu pojedynczych ppm. Przebadano także powtarzalność wyników pomiarów w kilku egzemplarzach czujników.
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Fragmentomic analysis of biopeptides in silico released from milk proteins
PublikacjaThe fragmentomic-assisted method was employed to predict the biological potential of peptides derived from milk proteins hydrolyzed by papain and bromelain. Firstly, protein sequences were acquired from the BIOPEP-UWM database and then hydrolyzed by the above enzymes using a BIOPEP-UWM tool called “Enzyme(s) action”. The released peptides were defined as parent peptides and further analyzed for the presence of shorter peptidic...
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Magneto-thermal convection of low concentration nanofluids
PublikacjaThe main aim of this paper was to analyze possible utilization of the low concentration nanofluids and the magnetic field to enhance heat transfer. The studied fluids were based on water with an addition of copper particles (40-60 nm diameter). They belonged to the diamagnetic group of materials. As a first attempt to stated target the analysis of enclosure placed in the maximal value of square magnetic induction gradient was carried...
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Closed-loop stimulation of temporal cortex rescues functional networks and improves memory
PublikacjaMemory failures are frustrating and often the result of ineffective encoding. One approach to improving memory outcomes is through direct modulation of brain activity with electrical stimulation. Previous efforts, however, have reported inconsistent effects when using open-loop stimulation and often target the hippocampus and medial temporal lobes. Here we use a closed-loop system to monitor and decode neural activity from direct...
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On Radar DoA Estimation and Tilted Rotating Electronically Scanned Arrays
PublikacjaWe consider DoA estimation in a monopulse radar system employing a tilted rotating array. We investigate the case of nonzero steering angles, in which case the mapping between the target’s azimuth and elevation in the global coordinate system and their counterparts in the array local coordinate system becomes increasingly nonlinear and coupled. Since estimating the azimuth using coherently integrated signals might be difficult because...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublikacjaMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Application of OFDM technique to underwater acoustic data transmission
PublikacjaPerformances of underwater acoustic communication (UAC) digital systems are strongly related to specific transmission properties of the underwater channel. Depending on the characteristics of the channel, an architecture and modulation techniques are usually implemented that are known as reliable solutions for data transmission in difficult radio channels. The OFDM technique seems to be the most promising nowadays. The parameters...
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Photoconduction and magnetic field effect on photoconduction in hole-transporting star-burst amine (m-MTDATA) films
PublikacjaPhotoconduction and magnetic field effect on photoconduction have been investigated as a function of electric field strength, excitation light intensity and wavelength in vacuum evaporated films of m-MTDATA (4,4′,4″-tris(N-(3-methylphenyl)-N-phenylylamino) triphenylamine), the starburst amine commonly used as hole-transporting material in organic light-emitting diodes. The photocurrent is found to be generated by the singlet exciton...
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Resistance noise in tio2-based thin film gas sensors underultraviolet irradiation
PublikacjaBadano możliwości wykorzystania fluktuacji rezystancji w cienkich warstwach TiO2 do wykrywania gazów. Pomiary przeprowadzono, gdy próbka była oświetlona promieniowaniem ultrafioletowym o długości 370nm, w obecności gazu H2S. Stwierdzono, że fluktuacje rezystancji są indukowane promieniowaniem ultrafioletowym i pozwalają na wykrycie obecności H2S w stężeniu do 1.5 ppm.
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PROBABILISTIC ANALYSIS OF A SPACE TRUSS BY MEANS OF A MULTIDIMENSIONAL VARIABLE DESCRIPTION
PublikacjaThe objective of this paper is to present a variant of the point estimate method (PEM) to determine mean values and standard deviations of limit loads of engineering structures. This approach is illustrated by limit state analysis of a space truss, considering geometric and material imperfections. The calculations were performed for different random models, so the influence of random parameters on the limit load of the truss can...
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Wpływ parametrów eksploatacyjnych oraz przecieków na wartość skoków ciśnienia w pompie tłoczkowej z rozrządem krzywkowym
PublikacjaPublikacja stanowi kontynuację artykułu "Analiza zjawisk dynamicznych w komorze cylindrowej pompy PWK o zmiennej wydajności" z monografii Cylinder 2010. Praca stanowi uszczegółowienie wcześniejszej publikacji oraz jej rozszerzenie o wyniki badań oraz symulacji, a także szczegółowo porusza temat przecieków w oknie rozrządu, który we wcześniejszych publikacjach był tylko wspomniany.
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Is There any Demand for the Workers Aged 50+ in Poland?
PublikacjaThe process of ageing affects all the European Union Member States, including Poland. According to forecasts by the Central Statistical Office, in 2035, the population of Poland will decrease in relation to 2010 by more than 2 million, and the share of people aged 50+ in the total population will increase from 34.8% to 46.6% (Prognoza ludności 2009). In the context of current and projected demographic changes, a discussion is taking...