Filtry
wszystkich: 2594
wybranych: 1971
-
Katalog
- Publikacje 1971 wyników po odfiltrowaniu
- Czasopisma 3 wyników po odfiltrowaniu
- Osoby 41 wyników po odfiltrowaniu
- Wynalazki 1 wyników po odfiltrowaniu
- Projekty 5 wyników po odfiltrowaniu
- Laboratoria 1 wyników po odfiltrowaniu
- Zespoły Badawcze 1 wyników po odfiltrowaniu
- Kursy Online 97 wyników po odfiltrowaniu
- Wydarzenia 5 wyników po odfiltrowaniu
- Dane Badawcze 469 wyników po odfiltrowaniu
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: EWOLUCJA FORM OŚWIETLENIOWYCH
-
Automatic Clustering of EEG-Based Data Associated with Brain Activity
PublikacjaThe aim of this paper is to present a system for automatic assigning electroencephalographic (EEG) signals to appropriate classes associated with brain activity. The EEG signals are acquired from a headset consisting of 14 electrodes placed on skull. Data gathered are first processed by the Independent Component Analysis algorithm to obtain estimates of signals generated by primary sources reflecting the activity of the brain....
-
Multibeam Echosounder and LiDAR in Process of 360-Degree Numerical Map Production for Restricted Waters with HydroDron
PublikacjaIn order to increase the safety of inland navigation and facilitate the monitoring of the coastal zone of restricted waters, a model of multi-sensory fusion of data from hydroacoustic and optoelectronic systems mounted on the autonomous survey vessel HydroDron will be developed. In the research will be used the LiDAR laser scanner and multibeam echosounder. To increase the visual quality and map accuracy, additionally side scan...
-
Implementation of the FOPID Algorithm in the PLC Controller - PWR Thermal Power Control Case Study
PublikacjaIn the paper authors describe proposition of design and verification procedures of the discrete Fractional Order PID (FOPID) algorithm for control of the Pressurized Water Reactor (PWR) thermal power near its nominal operating point. The FOPID algorithm synthesis consists of: off-line optimal tunning of its parameters in continuous time-domain with LQ (Linear Quadratic) performance index and simplified models of nuclear reactor...
-
Relicts of the 16th-century cellar by the St Mary's Church in Gdansk / Relikty piwnicy z XVI w. przy kościele Wniebowzięcia NMP w Gdańsku
PublikacjaSaint Mary’s church in Gdańsk, one of the largest brick Gothic temples in the World, has got no external chapels – except the House of Councils. Its architectural form, however, is not the result of implementation of one project, but realization of a few transforming concepts. The discovery of the relicts of the 16 th century cellars, located in the corner of the transept and the northern aisle, gives an idea of the process...
-
Application of the Barkhausen effect probe with adjustable m agnetic field direction for stress state determination in the P91 ste el pipe
PublikacjaThe paper presents the results of application of a novel Barkhausen effect (BE) probe with adjustable magnetizing field direction for the stress level evaluation in ferromagnetic materials. The investigated sample was in a form of a pipe, made of P91 steel that was anisotropic due to the production process. The measurements were performed before and after welding, revealing the influence of welding process on the residual stress...
-
The Drop-in-Drop Encapsulation in Chitosan and Sodium Alginate as a Method of Prolonging the Quality of Linseed Oil
PublikacjaNowadays, the encapsulation of sensitive products by various techniques has become popular as a promising preservation method. In particular, this applies to oils with a high content of unsaturated fatty acids and a high susceptibility to deterioration. This work presents the possibility of using a chitosan and sodium alginate in the form of a hydrogel membrane to protect food ingredients such as linseed oil, which is stored in...
-
Wykorzystanie substancji znacznikowych w badaniach stanu środowiska
PublikacjaMonitoring środowiska stanowi jeden z głównych obszarów analityki chemicznych, którego rozwój obserwuje się na przestrzeni ostatnich lat. Dzięki temu możliwe jest rozwiązywanie problemów związanych ze zmianami zachodzącymi w różnych ekosystemach z uwzględnieniem poszanowania środowiska. Jedną z form uzyskiwania miarodajnych informacji na temat stanu środowiska może być stosowanie substancji znacznikowych, których stosowanie umożliwia...
-
Detection of debonding in adhesive joints using Lamb wave propagation
PublikacjaAdhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form...
-
Profile irregularities of turned surfaces as a result of machine tool interactions
PublikacjaThe paper describes the influence of the machining operation on a surface, which disturbs the projection of the tool profile in the form of its relative movements with respect to the object. The elements of the machine tool undergo constant wear during the machining process, it is therefore important to recognize the effects of their influence on the surface's irregularities. Amplitude-frequency analysis of lateral profiles has...
-
Searching by heterogeneous agents
PublikacjaIn this work we introduce and study a pursuit-evasion game in which the search is performed by heterogeneous entities. We incorporate heterogeneity into the classical edge search problem by considering edge-labeled graphs: once a search strategy initially assigns labels to the searchers, each searcher can be only present on an edge of its own label. We prove that this problem is not monotone even for trees and we give instances...
-
Reactivity of bulky aminophosphanes towards small molecules: Activation of dihydrogen and carbon dioxide by aminophosphane/borane frustrated Lewis pairs
PublikacjaA series of mono- and bisaminophosphanes with formulas R2NPR’R’’ and (R2N)2PR’ (R = iPr, Cy; R’ = Ph, Cy; R’’ = iPr) were characterized by X-ray analysis, NMR spectroscopy and computational methods. The common structural futures of these species are short and polarized PAN bonds, a pyramidal geometry at the P atom and an almost planar geometry at the N atoms. According to DFT calculations, these...
-
Folding‐upon‐repair DNA nanoswitches for monitoring DNA repair enzymes activity
PublikacjaWe demonstrate here a new class of DNA‐based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding‐upon‐repair DNA nanoswitches are synthetic DNA sequences containing O6‐methyl‐guanine (O6‐MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation...
-
Characterization of herbal teas containing lime flowers – Tiliae flos by HPTLC method with chemometric analysis
PublikacjaLinden trees are a source of food products called lime flowers (Tiliae flos), traditionally used in the form of infusion for the treatment of feverish colds and coughs. Lime flowers should include flowers of Tilia cordata Mill, T.x europaea L., and T. platyphyllos Scop. or a mixture of these. The aim of current research was to establish a fast, sensitive HPTLC (high-performance thin-layer chromatography) method that would allow...
-
Experimental Investigations of Forced Convection of Nanofluids in Smooth, Horizontal, Round Tubes: A Review
PublikacjaA comprehensive review of published works dealing with experimental studies of forced convection heat transfer of nanofluids is presented. The survey is limited to straight, smooth, and round tubes. Moreover, only mono nanofluids exhibiting Newtonian behaviour are considered. Works on experimental research of forced convection in tubes are presented in a chronological order in the first part of the article. In this part, attention...
-
Polynomial analysis as a new way of describing dynamic impedance spectra – Differential and relative impedance spectra
PublikacjaModel measurements of an equivalent electrical system were carried out using the technique of Dynamic Electrochemical Impedance Spectroscopy. The measurement took the form of potentiodynamic changes imposed on the tested system. Using the possibility of continuous impedance measurements, an attempt was made to develop an original and innovative method of analyzing impedance spectrograms, which is termed polynomial analysis. As...
-
Global Digital Technology Convergence: Driving Diffusion via Network Effects
PublikacjaSince the 1970s, we have witnessed unprecedented diffusion of digital technologies in both speed and geographic coverage. These technologies are pervasive and disruptive, and lead to profound shifts and transformations in societies and economies. Many claim that emerging network externalities are the principal phenomenon driving the process of technology diffusion and determining its in-time dynamics. This book analyses the unique...
-
Dissolution of Nb-doped hydroxyapatite prepared via low-temperature mechanochemical method: Spectroscopy studies
PublikacjaCalcium phosphate glass ceramics with nominal hydroxyapatite stoichiometry doped with niobium were synthesized using simple as well as low-temperature mechanochemical method and then in the form of compressed pellet were submitted to the static dissolution process in distilled water for one month. The results of structural analysis, performed mainly on the base of spectroscopic methods such as: infrared absorption spectroscopy,...
-
A novel approach exploiting properties of convolutional neural networks for vessel movement anomaly detection and classification
PublikacjaThe article concerns the automation of vessel movement anomaly detection for maritime and coastal traffic safety services. Deep Learning techniques, specifically Convolutional Neural Networks (CNNs), were used to solve this problem. Three variants of the datasets, containing samples of vessel traffic routes in relation to the prohibited area in the form of a grayscale image, were generated. 1458 convolutional neural networks with...
-
Simulation Studies of Control Systems for Doubly Fed Induction Generator Supplied by the Current Source Converter
PublikacjaThe control system for a Doubly Fed Induction Generator (DFIG) supplied by a grid-connected Current Source Converter (CSC) is presented in this paper. Nonlinear transformation of DFIG model to the multi-scalar form is proposed. The nonlinear control strategy of active and reactive power of DFIG is realized by feedback linearization. In the proposed control scheme, the DFIG model and CSI parameters are included. Two Proportional-Integral...
-
Woda jako element przyrodniczy w przestrzeni zamieszkiwania. Ideowe formy architektoniczne
PublikacjaMożna obecnie zaobserwować nasilające się zjawisko pozamiejskich migracji. Sprzyja im dogodność warunków zamieszkiwania poza miastem. Pojezierze Kaszubskie to obszar, gdzie powstaje wiele pozamiejskich, czasowo zamieszkiwanych domów. Często lokowane są one pobliżu jezior i rzek. Wydaje się, że woda stanowi szczególny walor tych miejsc. Nawiązywane poprzez nią relacje i poczucie współuczestnictwa skłoniły do poszukiwania szczególnych...
-
Architektoniczne przestrzenie wspólne dizajnu i sztuki
PublikacjaW aspekcie współczesnego wszechobecnego konsumpcjonizmu i ograniczonych możliwości dotarcia do odbiorcy, role obiektów należących do sztuk czystych przejmują obiekty będące wytworami projektantów w zakresie sztuk użytkowych, w tym architektów. Jednocześnie sztuka poszukuje nowych form i środków wyrazu, żeby wzbudzić zainteresowanie. Rozpatrywanym obiektem jest Dom. Oczywistą jego odsłoną jest spełnienie oczekiwanej funkcji wynikającej...
-
Wide-field magnetometry using nitrogen-vacancy color centers with randomly oriented micro-diamonds
PublikacjaMagnetometry with nitrogen-vacancy (NV) color centers in diamond has gained significant interest among researchers in recent years. Absolute knowledge of the three-dimensional orientation of the magnetic field is necessary for many applications. Conventional magnetometry measurements are usually performed with NV ensembles in a bulk diamond with a thin NV layer or a scanning probe in the form of a diamond tip, which requires a...
-
Glass-ceramic joining of Fe22Cr porous alloy to Crofer22APU: interfacial issues and mechanical properties
PublikacjaThis work deals with the joining of porous Fe22Cr ferritic stainless steel to a dense Crofer22APU plate by using a silica-based, Ba-containing glass-ceramic. The chemical and interfacial stability and the mechanical properties of the joints were evaluated before and after thermal ageing at 700 ◦C for 500hrs. The sintering behaviour of the glass was assessed by using heating stage microscopy (HSM) to study the influence of a porous...
-
The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures
PublikacjaSubstances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist,...
-
Convenient and efficient N-methylation of secondary amines under solvent-free ball milling conditions
PublikacjaIn the present work, we report the development of a rapid, efcient, and solvent-free procedure for the N-methylation of secondary amines under mechanochemical conditions. After optimization of the milling parameters, a vibrational ball mill was used to synthesize 26 tertiary N-methylated amine derivatives in a short time of 20 min (30 Hz frequency) and high yields ranging from 78 to 95%. An exception was compounds having a hydroxyl...
-
Microextraction by packed sorbent: Uncommon detection techniques, sorbents, samples and analytes
PublikacjaAmong sample preparation approaches, the most desirable are procedures that ensure high efficiency and reproducibility, that are cheap, fast and simple, that minimize the number of operational steps and that require a small amount of sample and solvent and are thus environmentally friendly. Microextraction by packed sorbent (MEPS) is a miniaturized form of solid-phase extraction, the use of which has been continuously expanding...
-
Selective monitoring of noise emitted by vehicles involved in road traffic
PublikacjaAn acoustic intensity probe was developed measures the sound intensity in three orthogonal directions, making possible to calculate the azimuth and elevation angles, describing the sound source position. The acoustic sensor is made in the form of a cube with a side of 10 mm, on the inner surfaces of which the digital MEMS microphones are mounted. The algorithm works in two stages. The first stage is based on the analysis of sound...
-
Generalized Chebyshev Bandpass Filters With Frequency-Dependent Couplings Based on Stubs
PublikacjaThis paper presents an accurate synthesis method for inline and cross-coupled generalized Chebyshev bandpass filters with frequency-dependent couplings implemented via open and short stubs. The technique involves the synthesis of a lumped-element prototy pe in the form of a coupling matrix with a frequency-dependent term and the conversion of this prototype to a distributed-element mode l composed of sections of TEM lines. This...
-
The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges
PublikacjaPresent-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters...
-
Diamond investments – Is the market free from multiple price bubbles?
PublikacjaThe following study aims to investigate whether multiple price bubbles, in which the quoted market price of diamonds significantly deviates from their fundamental value, exist in the diamond market. It was conducted using ADF, SADF and GSADF tests, with the latter found to be an optimal form of evaluating the analysed issue. The presented results support the conclusion that the diamond market is not free from periods defined as...
-
Precipitation of calcium carbonate in the presence of rhamnolipids in alginate hydrogels as a model of biomineralization
PublikacjaThis paper reports the effects of rhamnolipids presence in the alginate hydrogel and CO32- solution, on the precipitation of CaCO3 in the Ca2+ loaded alginate hydrogel. Characteristics of the formed particles are discussed. Model conditions containing alginate hydrogel and rhamnolipids were used in order to mimic the natural environment of biomineralization in biofilms. It has been shown that rhamnolipids affect the characteristics...
-
Regeneration Project of Market Places GOSPOSTRATEG – “Polanki” Market in Gdańsk-Oliwa Pilot Project Monitoring Dataset
PublikacjaThe dataset entitled Monitoring of activities carried out as part of prototyping and implementation of the pilot project in the area of the “Polanki” market and its direct neighbourhood, in the Gdańsk-Oliwa district, step1; stage from July 2020 year contains tabular monitoring lists (quantitative and qualitative documentation report in the form of tables) of activities carried out as part of the prototyping and implementation of...
-
Accuracy of the Discrete Green's Function Formulation of the FDTD Method
PublikacjaThis paper reports an evaluation of the accuracy of the discrete Greens function (DGF) formulation of the finite-difference time-domain (FDTD) method. Recently, the closed-form expression for the DGF and its efficient numerical implementation were presented, which facilitates applications of the DGF in FDTD simulations of radiation and scattering problems. So far, the accuracy of the DGF formulation of the FDTD method has been...
-
Effect of waviness and roughness components on transverse profiles of turned surfaces
PublikacjaThis paper presents the authors method of simultaneous analysis of roughness and waviness irregularity components, with the aim of better defining the key qualities and characteristics.Periodical surface machining traces may be analyzed spectrally, with the irregularity's peaks and troughs being used to define the wave's amplitude.In this work the standard composition for filtering waviness and roughness components of a surface...
-
Zastosowanie symulacji metodą różnic skończonych w dziedzinie czasu (FDTD) w kształceniu inżynierów w zakresie optyki i elektrodynamiki
PublikacjaZrozumienie zjawisk związanych z propagacją fal elektromagnetycznych stanowi kluczowy etap kształcenia inżynierów w dziedzinach związanych z optyką, elektroniką oraz telekomunikacją. Oprócz opanowania aparatu matematycznego oraz metod projektowych istotne jest intuicyjne zrozumienie treści przekazywanych podczas kursów optyki i elektrodynamiki. W realizacji tego celu praktyczną pomoc dydaktyczną stanowić mogą wizualizacje i symulacje...
-
Analytical procedures for quality control of pharmaceuticals in terms of residual solvents content: Challenges and recent developments
PublikacjaResidual solvents play an important role in the synthesis of drugs and in product formulations. In addition, they pose a serious problem, that is toxicity, as many of them exhibit toxic or environmentally hazardous properties. Therefore, constant monitoring of quality control is needed. In this study, we present an overview of regulatory and general methods described by various pharmacopoeias. Then, the most commonly used methodologies...
-
Non-metaldoped TiO2 nanotube arrays for high efficiency photocatalytic decomposition of organic species in water
PublikacjaTitanium dioxide is a well-known photoactive semiconductor with a variety of possible applications. The procedure of pollutant degradation is mainly performed using TiO2 powder suspension. It can also be exploited an immobilized catalyst on a solid support. Morphology and chemical doping have a great influence on TiO2 activity under illumination. Here we compare photoactivity of titania nanotube arrays doped with non-metal atoms:...
-
Synthesis and biological evaluation of novel analogues of batracylin with synthetic amino acids and adenosine: an unexpected effect on centromere segregation in tumor cells through a dual inhibition of topoisomerase IIa and Aurora B
PublikacjaIn the search for new anticancer agents we designed and synthesized batracylin derivatives with linking synthetic amino acid side chains of different lengths and adenosine. Unexpectedly, we have found that in water and the culture media adenosine–amino acid–BAT conjugates form supramolecular structures and this prevents these compounds from entering cells. Consequently, these compounds exerted no biological activity when tested...
-
Features extraction from the electrocatalytic gas sensor responses
PublikacjaOne of the types of gas sensors used for detection and identification of toxic-air pollutant is an electrocatalytic gas sensor. The electrocatalytic sensors are working in cyclic voltammetry mode, enable detection of various gases. Their response are in the form of I-V curves which contain information about the type and the concentration of measured volatile compound. However,...
-
Spectral reflectance and transmission modeling of multi-cavity Fabry-Pérot interferometer with ZnO thin films
PublikacjaIn this paper spectral reflectance and transmission of a low-coherence fiber-optic Fabry-Pérot interferometer with thin ZnO layers is analyzed using a multi-cavity approach. In the investigated setup two standard single-mode optical fibers (SMF-28) with thin ZnO films deposited on their end-faces form an extrinsic Fabry-Pérot interferometer with air cavity. Calculations of the spectral response of the interferometer were performed...
-
The landscape in the informal education of the youngest
PublikacjaThe European Landscape Convention, adopted in 2000, aims to promote the protection, management and planning of landscapes and to organise cooperation on landscape-related issues. Countries that ratified the Convention undertook to introduce activities that would promote public education on the subject. In Poland, the Ministry of Education has identified schools as the place to implement...
-
Knowledge economics and the demand for higher education
PublikacjaThis article suggests that the decreased demand for higher education in Poland is partially caused due to the changes in consumer preferences. The appearance of a cheap and highly accessible form of knowledge offered by the massive open online courses is presumed here to have an effect on the demand for formal higher education. This article proposes an additional perspective to the research on knowledge consumption, especially...
-
Pasmo Gdańsk-Kartuzy a teoretyczny model urbanizacji funkcjonalno-przestrzennej
PublikacjaOpracowanie przypomina koncepcje tzw. "korytarzy osiedleńczych" tworzonych przez pasma zurbanizowane, w skład których wchodziły wyodrębnione strukturalne jednostki osadnicze. Pasma te były obsługiwane przez wiązki infrastruktury technicznej a dostępność do poszczególnych jednostek i ich wielkości wynikały z warunków i możliwości technicznych środków komunikacji masowej, oraz możliwości fizycznych człowieka określanych parametrami...
-
Proximal primal–dual best approximation algorithm with memory
PublikacjaWe propose a new modified primal–dual proximal best approximation method for solving convex not necessarily differentiable optimization problems. The novelty of the method relies on introducing memory by taking into account iterates computed in previous steps in the formulas defining current iterate. To this end we consider projections onto intersections of halfspaces generated on the basis of the current as well as the previous...
-
Analiza stanu nawierzchni i klas pojazdów na podstawie parametrów ekstrahowanych z sygnału fonicznego
PublikacjaCelem badań jest poszukiwanie parametrów wektora cech ekstrahowanego z sygnału fonicznego w kontekście automatycznego rozpoznawania stanu nawierzchni jezdni oraz typu pojazdów. W pierwszej kolejności przedstawiono wpływ warunków pogodowych na charakterystykę widmową sygnału fonicznego rejestrowanego przy przejeżdżających pojazdach. Następnie, dokonano parametryzacji sygnału fonicznego oraz przeprowadzano analizę korelacyjną w celu...
-
Przyczyny uszkodzeń i sposób naprawy posadzki ze styrobetonu
PublikacjaW artykule opisano uszkodzenia, badania i sposób naprawy posadzki wykonanej na istniejącym stropie żelbetowym o powierzchni ok. 1050 m2 i podłożu ze styrobetonu. W posadzce stwierdzono znaczne uszkodzenia w postaci zarysowań, odspojeń i nierówności. W celu określenia ich przyczyn wykonano badania in situ oraz badania laboratoryjne. Stwierdzono, że przyczyną powstania uszkodzeń są błędy wykonawcze. Wykonano próbną naprawę uszkodzeń...
-
Estetyka domu jak element warunkujący poczucie przynależności w procesie zamieszkiwania
PublikacjaDom jest formą schronienia, która stanowi przedmiot w złożonym procesie zamieszkiwania. Jednym z aspektów decydujących o doświadczaniu poczucia utożsamiania w tym procesie jest estetyka tego domu. Dbałość o jej spójność z oczekiwaniami przyszłych mieszkańców i wpasowanie w zastane otoczenie wydają się oczywistym zadaniem architekta. Jednak w przypadku istniejących osiedli mieszkaniowych wielorodzinnych, zwanych potocznie blokowiskami,...
-
Kinematyka jako odpowiedź na współczesną potrzebę tworzenia przestrzeni = KINEMATICS AS AN ANSWER TO THE CURRENT NEED TO CREATE A RE-CONFIGURABLE SPACE
PublikacjaPrzestrzeń re-konfigurowalna pojawiły się w sztuce i architekturze już w pierwszej połowie XX wieku jako forma odpowiedzi na na pytania, które stawia przed nią świat. Nasze życie i potrzeby zmieniają się niesamowicie dynamicznie. Postfordowski model społeczeństwa sprzyja generowaniu zjawisk, których jeszcze rok temu nie brano pod uwagę. Stąd architektura próbuje stanowić odpowiedź na problemy jeszcze niezaistniałe. Jedną z jej...
-
Application and modelling of Shape-Memory Alloys for structural vibration control: State-of-the-art review
PublikacjaOne of the most essential components of structural design for civil engineers is to build a system that is resistant to environmental conditions such as harsh chemical environments, and catastrophic disasters like earthquakes and hurricanes. Under these circumstances and disturbances, conventional building materials such as steel and concrete may demonstrate inadequate performance in the form of corrosion, deterioration, oxidizing,...
-
MIĘDZY LĄDEM I WODĄ Kształtowanie połączeń lądu i wody na terenach poprzemysłowych
PublikacjaPublikacja poświęcona jest modyfikacjom planów obszarów wodnych i form ich granic dokonywanym w obrębie obszarów poprzemysłowych. Co istotne, modyfikacje takie wpisane są w historię wszystkich, związanych z akwenami i ciekami wodnymi struktur miejskich. Można zauważyć, że szczególnie te, realizowane w czasie ostatnich dekad, związane są ściśle z przestrzennymi i funkcjonalnymi przeobrażeniami miast. Uwalnianie znacznych powierzchni...