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Search results for: HIGH-SPEED DRIVE
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Possibility to use engine compression ignition engines in floating power plants marine
PublicationCompression-ignition engines used in ship technology as main propulsion engines are large units reaching even to 50-60 MW. The engines can be used in power industry for electricity generation in a simple or combined steam turbine system in combined heat and power plants. The leading engine in such an arrangement is an internal-combustion piston engine. The main propulsion engines are used in large piston internal-combustion engines...
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ARRIERE-GARDE IN ARCHITECTURE, AS A RESPONSE TO POST-POSTMODERN REALITY
PublicationThe article presents a general discussion on the direction of contemporary architecture. We can freely speak that postmodernity, understood in its philosophical core as a search for meaning in architecture, as a strategy of building our environment is over. What comes next? Some say, from lack of better naming, that we live in post-postmodern times. Term post-postmodernity is a call for new strategy of shaping our societies and...
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The effect of the motor filters on earth fault current waveform in circuits with variable speed drives
PublicationIn circuits with variable speed drives distorted earth fault current flows. Earth fault current distortion influences the threshold of ventricular fibrillation. This paper presents earth fault current distortion in circuits with variable speed drives when motor filter is used. Two types of motor filter are analyzed. For every type of filter the effect of earth fault current distortion on ventricular fibrillation is evaluated.
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The effect of the motor filters on earth fault current waveform in circuits with variable speed drives
PublicationIn circuits with variable speed drives distorted earth fault current flows. Earth fault current distortion influences the threshold of ventricular fibrillation. This paper presents earth fault current distortion in circuits with variable speed drives when motor filter is used. Two types of motor filter are analyzed. For every type of filter the effect of earth fault current distortion on ventricular fibrillation is evaluated.
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The Method of Finding the Optimal Spindle Speed When Milling Flexible Details
PublicationThe paper presents a new method of vibration reduction during milling of flexible details. The method consists in selecting the optimal spindle speed, based on the natural frequency of the workpiece. For this purpose, an original method was created, which is based on minimizing the work of cutting forces in the direction of the depth of cutting. The effectiveness of the method has been proved by comparing the RMS values of vibration...
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Internationalization patterns of Polish family high-tech firms
PublicationThe objective of the article is to explore internationalisation patterns of family high-tech firms, especially their internationalisation motives, intensity, speed, and entry modes. The empirical part adopts a quantitative approach. The results of the survey are presented on the sample of 263 high-tech production firms from Poland, including 101 family firms. The survey was conducted in all 16 Polish regions. The calculations from...
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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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Experimental comparison of the transition speed of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationA journal bearing test bench is used to find the transition speed between the hydrodynamic and mixed lubrication regimes for a modified magnetorheological (MR) fluid. It is shown that the transition speed of the bearing can be reduced by applying a local magnetic field near minimum film when it is lubricated with the MR fluid, and that this will only marginally increase friction. The lubricating performance of the MR fluid is compared...
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Preliminary studies on the effect of feed speed on the colour change of wood
PublicationThis paper presents the results of preliminary analyses of the effect of cutting parameters on changes in the colour of wood. Beech wood cut with use circular saw was analysed. The cutting parameter tested was the feed speed, represented by the feed per tooth. Sawing processes with different feed per tooth ranging from 0.0008 mm to 0.09 mm were analysed. It was observed that over the entire range of feed rate per tooth analysed,...
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Analysis of positioning error and its impact on high frequency properties of differential signal coupler
PublicationThis paper presents the analysis of the effect of differential signal coupler positioning accuracy on its high frequency performance parameters for contact-less high speed chip-to-chip data transmission on PCB application. Our considerations are continuation of the previous works on differential signal coupler concept, design methodology and analysis for high speed data transmission monitoring. The theoretical analysis of possible...
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Research of electric drive systems with real time software configurable control
PublicationПредмет исследования. Представлен учебно-лабораторный стенд для исследования систем управления элек- троприводами. Стенд используется для обучения студентов системам управления электроприводами и предна- значен для повышения эффективности усвоения материала. Метод. В основу предлагаемого решения положен метод взаимного нагружения электрических машин, питаемых от силовых преобразователей с общим звеном постоянного тока. Это позволяет...
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Investigation of the vertical distribution of the sound speed of the Gulf of Gdansk in the years 2000-2010
PublicationThe conditions of the acoustic wave propagation in the southern Baltic are much more complex than in other shallow waters. In the typical shallow water, seasonal changes in acoustical conditions in the upper layer, of the depth of about 60-70 m, are observed. They are caused by variation of the annual meteorological conditions. Most often, in the deep water layer, acoustical conditions are stable throughout the year. However, in...
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The Development of a Combined Method to Quickly Assess Ship Speed and Fuel Consumption at Different Powertrain Load and Sea Conditions
PublicationDecision support systems (DSS) recently have been increasingly in use during ships operation. They require realistic input data regarding different aspects of navigation. To address the optimal weather routing of a ship, which is one of the most promising field of DSS application, it is necessary to accurately predict an actually attainable speed of a ship and corresponding fuel consumption at given loading conditions and predicted...
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Analysis and design improvement of high class roads’ arched sections in Poland
PublicationAlthough Polish road network standards, in particular higher classes of roads are improving dynamically the number of fatalities on the network is still higher that EU’s average. Ensuring road safety and high maintaining standards is a complex issue and one that poses a major challenge for all road authorities. Road accidents at high speed roads characterize specially serious material and social consequences, thus research into...
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Evolutionary sets of safe ship trajectories with speed reduction manoeuvres within traffic separation schemes
PublicationIn the previous paper the author presented the evolutionary ship trajectory planning method designed to support Traffic Separation Schemes (TSS). This time the extensions of this method are described which allow to combine evolutionary trajectory planning with speed reduction manoeuvres. On TSS regions with higher than usual density of traffic and smaller distances between ships, the course alterations alone are not always sufficient...
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Ionic liquid as morphology-directing agent of two-dimensional Bi2WO6: New insight into photocatalytic and antibacterial activity
PublicationAn efficient and durable utilization of light to drive photocatalytic reactions still requires the overcoming of barriers. Herein, two-dimensional (2D) ultrathin IL_Bi2WO6 (IL_BWO) photocatalysts were prepared for the first time via ionic liquid-assisted hydrothermal route by adjusting the amount of tetrabutylammonium chloride [TBA][Cl], synthesis temperature and duration. IL played the role of morphology-directing agent given...
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Entropic Measures of Complexity of Short-Term Dynamics of Nocturnal Heartbeats in an Aging Population
PublicationTwo entropy-based approaches are investigated to study patterns describing differences in time intervals between consecutive heartbeats. The first method explores matrices arising from networks of transitions constructed following events represented by a time series. The second method considers distributions of ordinal patterns of length three, whereby patterns with repeated values are counted as different patterns. Both methods provide...
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High pressure spectroscopy of chromium doped LiTaO3crystals
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Marine propeller shaft bearings under low-speed conditions: water vs. oil lubrication
PublicationThe bearings used in shipbuilding, hydropower, and water pumps have undergone a metamorphosis in recent decades. Because of environmental regulations, lubrication with grease or mineral oil is prohibited. Thus, the standard solutions include water-lubricated bearings with polymer bushings or sealed systems lubricated with oil. When properly designed, assembled, and operated, bearings can operate reliably for years. However, specific...
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Chatter Vibration Surveillance by the Optimal-linear Control of Spindle Speed and Randomly Varying Spindle Speed
PublicationW artykule opisano dynamikę procesu skrawania smukłym frezem kulistym. Jako metodę nadzorowania drgań chatter zastosowano zmienną prędkość obrotową wrzeciona. Jest ona dobierna z wykorzystaniem energetycznego wskaźnika jakości co prowadzi do optymalno-liniowego sterowania prędkością obrotową. Dodatkowo zastosowano nadzorowanie drgań chatter poprzez losowo zmienną prędkość obrotową.
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Napęd elektryczny w motoryzacji = The electric drive in motorization
PublicationWyczerpujące się zasoby ropy naftowej sprzyjają rozwojowi spekulacji cen paliw na giełdach światowych. Jednocześnie postępujący efekt cieplarniany zmusza inżynierów do poszukiwania nośników energii oraz napędów, które mógłby być alternatywnym rozwiązaniem zaistniałej sytuacji ekonomicznej oraz ekologicznej. Użycie silników elektrycznych do napędu pojazdów samochodowych jest pewną alternatywą rozwiązującą problem wysokich cen paliw...
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Determining the operational loads of the hybrid metalworking machines drive
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Control of Sensorless Electric Drive with Inverter Output Filter
PublicationW artykule przedstawiono układ sterowanie silnikiem asynchronicznym pracyjący bez pomiaru prędkości obrotowej. Zastosowano nowy rodzaj obserwatora prędkości obrotowej będący połączeniem liniowego obserwatora oraz obserwatora zakłóceń. Jako zakłócenia potraktowano siłę elektromotoryczną indukowaną w silniku. Aby umożliwić poprawną pracę układu z filtrem wyjściowym falownika zastosowano symulator dynamiki filtru do wyznaczenia prądów...
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Multiparameter analysis of Stirling engine with Ericsson drive mechanism.
PublicationW pracy zaprezentowano wyniki optymalizacji parametrów konstrukcyjnych silnika Stirlinga o konfiguracji beta z mechanizmem korbowym Ericssona. Jako kryterium przyjęto maksymalizację mocy silnika. W pierwszym etapie poddano optymalizacji tylko parametry konstrukcyjne wymiennika ciepła (7 zmiennych) W drugim etapie do powyższych zmiennych decyzyjnych procesu optymalizacyjnego dołączono wymiary tłoka oraz parametry konstrukcyjne...
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Digital measurements of the feedback signals for observing behaviour of a drive.
PublicationW pracy omówiono sposoby badań przebiegu ruchu realizowanego przez napęd, w tym poprzez pomiar sygnałów sprzężeń zwrotnych. Przedstawiono różne typy błędów pomiaru sygnałów sprzężeń zwrotnych i ich oddziaływanie na wyniki.
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Hydraulic drive and control of the equipment of the small fishing cutter.
PublicationPrzedstawiono uwarunkowania i założenia techniczne oraz zaprojektowany i zrealizowany układ napędu i sterowania hydraulicznego urządzeń małego kutra rybackiego KR10. Pewna zmiana układu zrealizowanego wynikała z konieczności dostosowania go do tymczasowo zastosowanych urządzeń połowowych, odmiennych niż przewidywał projekt. Przedstawiono także informacje o wynikach prób morskich i dwumiesięcznego okresu eksploatacji w różnych,...
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An advanced low-cost sensorless induction motor drive
PublicationW artykule przedstawiono układ sterowania silnikiem asynchronicznym klatkowym pracujący bez pomiaru prędkości obrotowej. Układ zrealizowano na tanim procesorze stałoprzecinkowym. aspekty praktyczne realizacji układu rozpatrzono na podstawie uzyskanych wyników z symulacji i eksperymentu.
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Selection of the Electric Drive for the Wood Waste Compacting Unit
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Sensorless induction motor drive for electric vehicle application
PublicationW artykule przedstawiono układ napędowy pojazdu elektrycznego wykorzystujący niezawodny i tani silnik prądu przemiennego. Zastosowany trójfazowy silnik asynchroniczny klatkowy wymaga zasilaniaz falownika napięcia przekształcającego napięcie stałe z akumulatorów na napięcie przemienne. Wykonany tranzystorowy przekształtnik sterowany jest mikroprocesorowo. Zastosowany procesor realizuje algorytm sterowania polowo zorientowanego,...
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Predictive current controller for sensorless induction motor drive
PublicationPrzedstawiono układ bezczujnikowego sterowania dla napedu z silnikiem klatkowym przy zastosowaniu predykcyjnego regulatora pradu. Zastosowany obserwator adaptacyjny wykazuje dużą odporność na zmiany parametrów silnika. W obserwatorze obliczane są wartości sił elektromotorycznych wykorzystywane w procesie regulacji predykcyjnej pradu silnika. Pokazano wyniki badań symulacyjnych i eksperymentalnych.
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Autonomous Battery Drive in Trolleybuses: an Overview of Practical Examples
PublicationBattery electric buses are believed to be means of transportation of the future. However, despite the continuous development of electrochemical batteries technology and the multitude of electric buses on offer, it is still no proved solutions that can be widely used. Charging is the one of the weakness point of the electric buses. Trolleybuses are alternative for them. Especially, trolleybuses equipment with traction batteries...
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Examining Impact of Speed Recommendation Algorithm Operating in Autonomous Road Signs on Minimum Distance between Vehicles
PublicationAn approach to a new kind of recommendation system design that suggests safe speed on the road is presented. Real data obtained on roads were used for the simulations. As part of a project related to autonomous road sign development, a number of measurements were carried out on both local roads and expressways. A speed recommendation model was created based on gathered traffic data employing the traffic simulator. Depending on...
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Collaborative development model and strategies of multi-energy industry clusters: Multi-indicators analysis affecting the development of coastal energy clusters
PublicationThe paper explores Coastal Energy-Based Industrial Clusters (EBICs) and their role in advancing energy efficiency and sustainability through collaborative innovation. Economic growth theory and energy sustainability have been introduced into industrial clusters to illustrate indicators that have a greater impact on the development of EBICs. This paper proposes an EBICs development model based on the Cobb-Douglas function, in which...
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Thermodynamics and kinetics of amphotericin B self-association in aqueous solution characterized in molecular detail
PublicationAmphotericin B (AmB) is a potent but toxic drug commonly used to treat systemic mycoses. Its efficiency as a therapeutic agent depends on its ability to discriminate between mammalian and fungal cell membranes. The association of AmB monomers in an aqueous environment plays an important role in drug selectivity, as oligomers formed prior to membrane insertion – presumably dimers – are believed to act differently on fungal (ergosterol-rich)...
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Fuzzy Control of Waves Generation in a Towing Tank
PublicationThis paper presents the results of research related to the transformation of electrical energy into potential and kinetic energy of waves generated on the water surface. The waves are generated to model the environmental conditions for the needs of the model tests. The model tests are performed on model-scale objects to predict the features of full-scale maritime objects. It is done to improve human safety and the survivability...
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Key-Marker Volatile Compounds in Aromatic Rice (Oryza sativa) Grains: An HS-SPME Extraction Method Combined with GC×GC-TOFMS
PublicationThe aroma of rice essentially contributes to the quality of rice grains. For some varieties, their aroma properties really drive consumer preferences. In this paper, using a dynamic headspace solid-phase microextraction (HS-SPME) system coupled to a two-dimensional gas chromatography (GC×GC) using a time-of-flight mass spectrometric detector (TOFMS) and multivariate analysis, the volatile compounds of aromatic and non-aromatic...
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Modular high precision high current source for special applications — Simulation and verification
PublicationThis paper presents selected issues concerning realization of high precision high current source for special applications, where high demands of output parameters of such device are required. A new 80 kW prototype of modular high precision high current source is presented, where output current accuracy reaches 5x10-5. This paper presents also results of operation of the simulation model and of the prototype converter. In order...
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Bifurcation of equilibrium forms of a gas column rotating with constant speed around its axis of symmetry
PublicationWe will be concerned with the problem of deformation of the lateral surface of a column that rotates with constant speed around its axis of symmetry. The column is filled by a gas and our goal is to investigate the deformation of the lateral surface depending on the pressure of the gas.
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Running characteristics of aerodynamic bearing with self-lifting capability at low rotational speed
PublicationAn aerodynamic journal bearing that is capable of self-generating squeeze-film pressure is presented and its dynamic characteristics investigated numerically and experimentally. A numerical method based on a time marching static model was applied to assess the orbit trajectory path of the rotor upon a perturbation. Experimental results were obtained to validate the effect of the self- generated squeeze-film pressure on the stability...
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Sensorless Control of Induction Motor Based on Super-Twisting Sliding Mode Observer With Speed Convergence Improvement
PublicationThe super twisting sliding-mode observer (ST-SMO) has been proposed to achieve an effective method for alleviating low-order harmonics of measured quantities, issues related to DC drift, and suppression of chattering due to low-frequency sampling. The conventional ST-SMO, on the other hand, suffers from control delay in the convergence trajectory due to the system disturbance, resulting in decreased anti-disturbance capability...
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Optimisation of inland vessels' route speed.
PublicationW pracy przedstawiono rezultaty badań dotyczących metody doboru prędkości i oceny zapotrzebowanej mocy napędu statków śródlądowych, przydatnej zarówno we wstępnych etapach projektowania, jak i w zarządzaniu eksploatacją taboru śródlądowego, np. przy ustalaniu harmonogramu rejsów pasażerskich statków wycieczkowych. Do rozwiązania problemu zastosowano metodę optymalizacji nieliniowej z ograniczeniami, opartą na minimalizacji kosztu...
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Variable speed small hydropower plant
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Experimental Study of Flow Rate in Hydraulic Satellite Motor with the Rotating Case at a Low Constant Rotational Speed
PublicationIn this article was described the methodology for the experimental study of flows in the prototype of a satellite hydraulic motor with a rotating body. The experimental tests of the motor were carried out at a low constant rotational speed in a wide range of pressure drop in this motor. The constant rotational speed of the motor was kept by a worm gear. Based on the test results, the leakage characteristics in the flat gaps of...
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Five-Phase EV Drive with Switched-Autotransformer (LCCAt) Inverter
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Detection and compensation of torque harmonics in drive with induction motor and gear
PublicationUkład mechaniczny przeniesienia napędu jest stosowany w większości elektrycznych układów napędowych. Właściwości przekładni mechanicznej powodują występowanie drgań moemntu w układzie. Analiza tych drgań, mierzonych np. za pomoca akcelerometrów, umozliwia detekcję uszkodzeń przekładni. Z uwiagi na trudności pomiatrowe dąży się jednak do eleminacji układów pomiarowych drgań przez zastąpienie ich metodami obliczeniowymi. Znając...
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Electromagnetic Field Measurements of Bow Thruster Drive with Frequency Converter
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The influence of the motor filtrers on harmonic current emmision in the pro-ective connection of drive systems.
PublicationThis paper contains detailed analysis of currents in protective wire in engine supplied from frequency converter without any external filters added. It was found that the peak value of current in protective conductor of engine was about 1500 mA at frequencies 5 Hz 50 Hz. In the continuation of research the dU/dt type motor filter and the sinusoidal filter were tested. It was found that the current in protective wire decreased...
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Chemical Theory of Machines, basic principles of strength with examples of calculations
PublicationThis book encompasses the essential range of information on technical aspects of mechanical design. It was written primarily for the students and staff of chemistry faculties of technical universities, yet it may also be utilized by everyone, who ether would like to try or already enjoys designing, but cannot take advantage of typical stress & machine construction handbooks. These handbooks often require familiarity with the concepts...
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Possible quadrupole-order-driven commensurate-incommensurate phase transition in B20 CoGe
PublicationThe B20-type cobalt germanide CoGe was investigated by measuring the specific heat, resistivity, and 59Co nuclear magnetic resonance (NMR).We observed a phase transition at TQ = 13.7 K, evidenced by a very narrow peak of the specific heat and sharp changes of the nuclear spin-spin (T −1 2 ) and spin-lattice (T −1 1 ) relaxation rates. The fact that the entropy release is extremely small and the Knight shift is almost independent...
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Application of the ISE Optimized Proportional Control of the Wave Maker in a Towing Tank
PublicationThis paper presents the improvement of the wave maker control system. The wave maker is a facility widely used in hydromechanics laboratories to generate waves in towing tanks. It is equipped with an electrohydraulic drive and an actuator submerged into water. The waves are generated to model the environmental conditions for physical experiments, performed on reduced-scale models of maritime objects. The physical experiments allow...