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Search results for: spherical tanks
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The effects of urban vehicle traffic on heavy metal contamination in road sweeping waste and bottom sediments of retention tanks
PublicationDiffuse pollution formed during a surface runoff on paved surfaces is a source of heavy metals (HMs) of various origin. This research study indicates the connection between bottom sediments of retention tanks located on urban streams and road sweeping wastes (RSW) that migrate during surface runoff to the stormwater drainage systems with discharge to the retention tanks. Moreover, we test the primary sources of HMs in RSW by analysing...
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Spatial and vertical distribution analysis of heavy metals in urban retention tanks sediments: a case study of Strzyza Stream
PublicationConcentrations of seven heavy metals (HMs): Zn, Cu, Pb, Cd, Ni, Cr, and Fe in core samples of bottom sediments from four retention tanks (RTs) located along the Strzyza Stream in northern Poland (Gdansk) were measured to obtain a general view of sediment quality. The recognition of contamination and potential environmental impacts is the main aim of this paper. A total of 96 sediment samples were collected from eight sampling sites...
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COLLOIDS IN SEPTIC TANK EFFLUENT AND THEIR INFLUENCE ON FILTER PERMEABILITY
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Roll respose of ship fitted with passive stabilizing tank.
PublicationPrzedstawiono fizyczny i matematyczny model kołysań statku z biernym zbiornikiem stabilizacyjnym. Wyprowadzono równania ruchu i podano ich rozwiązania. Określono najistotniejsze zalecenia projektowe w oparciu o uzyskane rozwiązania. Wskazano kierunek poszukiwania optymalnych rozwiązań dla układu statek-bierny zbiornik stabilizacyjny.
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Analysis of Impulse Responses Measured in Motion in a Towing Tank
PublicationThe growing interest in developing autonomous underwater vehicles (AUVs) and creating underwater sensor networks (USNs) has led to a need for communication tools in underwater environments. For obvious reasons, wireless means of communication are the most desirable. However, conducting research in real conditions is troublesome and costly. Moreover, as hydroacoustic propagation conditions change very significantly, even during...
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Analysis of Impulse Responses Measured in Motion in a Towing Tank
PublicationThe growing interest in developing autonomous underwater vehicles (AUVs) and creating underwater sensor networks (USNs) has led to a need for communication tools in underwater environments. For obvious reasons, wireless means of communication are the most desirable. However, conducting research in real conditions is troublesome and costly. Moreover, as hydroacoustic propagation conditions change very significantly, even during...
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Decay properties of unstable Tonks-Girardeau gases from a split trap
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Feasibility Study for Food Intake Tasks Recognition Based on Smart Glasses
PublicationIn this exploratory study 13 adult test subjects have performed different food intake tasks while wearing a three axis accelerometer mounted at a temple of glasses. Two different algorithms for task recognition have been applied and compared. The retrospective data processing leads to better task recognition results when the frequency range of 50 Hz to 100 Hz is analysed within accelerometer signal recordings. A straightforward...
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Prediction of Processor Utilization for Real-Time Multimedia Stream Processing Tasks
PublicationUtilization of MPUs in a computing cluster node for multimedia stream processing is considered. Non-linear increase of processor utilization is described and a related class of algorithms for multimedia real-time processing tasks is defined. For such conditions, experiments measuring the processor utilization and output data loss were proposed and their results presented. A new formula for prediction of utilization was proposed...
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Pro-Ecological Activities in Polish Financial Institutions on the Example of Selected Banks
PublicationThe character of the role that banks play in the economy provides them with an opportunity to positively affect the environment on multiple levels. The article aimed at characterizing and evaluating pro-ecological activities occurring in financial institutions in Poland. It compares pro-ecological activities undertaken by three different banks operating on the Polish market: BOŚ Bank SA, BNP Paribas Bank Polska SA and PKO Bank...
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Central banks and the weaponization of inflation
EventsSerdecznie zapraszamy na kolejny webinar z cyklu Rethinking Economics Gdańsk.
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The evaluation methodology of corrosion protection of tanks from hull structural steels with Acoustic Emission use and first results of investigations
PublicationW referacie przedstawiono metodykę badań mającą na celu ocenę stopnia ochrony przed korozją konstrukcji zbiorników ładunkowych i balastowych wykonanych ze stali kadłubowych z wykorzystaniem Emisji Akustycznej (EA). W metodyce wykorzystano wymagania obowiązujących norm, standardów oraz doświadczenia zdobyte w dotychczasowych badaniach poświęconych zastosowaniu metody EA do wykrywania i lokalizacji źródeł korozji na statkach. Do...
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THE INVESTIGATION OF DENSITY CURRENTS AND RATE OF OUTFLOW FROM A SEPTIC TANK
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Analysis of tank safety with propane-butane on LPG distribution station
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Fixed roof to shell connection in tank with an internal floating cover.
PublicationReferat dotyczy projektowania połączenia dachu stałego zbiornika walcowego z płaszczem w przypadku zastosowania wewnętrznego przekrycia pływającego. Zaproponowano zastosowanie dodatkowego pierścienia usztywniającego, zabezpieczającego górną krawędź płaszcza zbiornika. Wyniki analiz z zastosowaniem metody elementów skończonych zamieszczono w formie map naprężeń.
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Deformations of the steel schell of a vertical cylindrical tank caused by underpressure
PublicationUnderpressure in a tank with a fixed roof may arise in the final stage of its construction as well as during its usage. This article presents stages of deformations of the tank shell and their development from the occurrence of the first deformation to either removal of the causes of underpressure or cracking of the steel shell.
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Reliability estimation of underground horizontal fuel tank limit states
PublicationFuel tanks are designed with regard to standard loads and operating conditions. The investigations of the paper show the impact of such factors as tank corrosion and other means on the variation of stress fields and deformation of the underground horizontal tank shell. The introduction of probabilistic methods allows for structural reliability assessment. While the computational time of the entire tank FEM model is high, the preliminary...
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DESIGN ERRORS CAUSE AN EMERGENCY OF THE REINFORCED CONCRETE TANK FOR COKE
PublicationThe quality of the developed design documentation and the maintenance of the technological regime during construction works have a decisive impact on the subsequent safety of the structure, as well as the safety of use of the building. The paper describes the defects and damages of an open, rectangular reinforced concrete tank for hot process water, which failed during a short period of operation. The article also presents the...
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CONTROL OF THE WAVES IN A TOWING TANK WITH THE USE OF A BLACK-BOX MODEL
PublicationThe paper describes an adaptive control system of the waves, implemented in the Ship Design and Research Centre, CTO S.A. The purpose of generating the waves in the towing tank is the modelling of the environmental conditions during hydrodynamic model tests. The tests are performed on scale models of towed or free running ships, anchored structures like oil rigs or bottommounted structures, e.g. wind turbines. In the towing tank...
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Design Equation for Stirring Fluid by a Stream Pump in a Circulating Tank
PublicationA circulating tank is a very useful theoretical scheme for many fluid-flow objects in several branches of engineering. The motion of the fluid in such objects can be induced in different ways. A stream pump provides an especially interesting possibility; however, the quantitative description of such devices shows some shortcomings. Such a device is analogous to a jet pump, thus has similar advantages (simplicity of construction,...
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Design of three control algorithms for an averaging tank with variable filing
PublicationAn averaging tank with variable filling is a nonlinear multidimensional system and can thus be considered a complex control sys-tem. General control objectives of such object include ensuring stability, zero steady state error and achieving simultaneously shortest possible settling time and minimal overshoot. The main purpose of this research work was the modelling and synthesis of three control systems for an averaging tank. In...
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Synthesis of a state feedback controller for an averaging tank with variable filling
PublicationIn paper, a nonlinear averaging tank with variable filling is considered. The main purpose of this research work was the modelling and control system synthesis of an averaging tank. The control objectives included ensuring stability and zero steady-state error of the system and achieving settling time as short as possible, while maintaining a minimal overshoot. In order to achieve the intended purpose, firstly a mathematical model...
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Results of acoustic emission tests of corrosion protection degree of ship steel tanks covered by means of protective coatings (Phase I)
PublicationThis paper presents methods and results of the 1st series of tests of acoustic emission (AE) signals, aimed at assessing degree of corrosion protection of a tank made of hull structural steel, protected by means of a protective coating combined from polyurethane layer and concrete filler. The tests were carried outin compliance with a method specially elaborated for application to the work in question. In the method were used requirements...
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A graph coloring approach to scheduling of multiprocessor tasks on dedicated machines with availability constraints
PublicationWe address a generalization of the classical 1- and 2-processor unit execution time scheduling problem on dedicated machines. In our chromatic model of scheduling machines have non-simultaneous availability times and tasks have arbitrary release times and due dates. Also, the versatility of our approach makes it possible to generalize all known classical criteria of optimality. Under these stipulations we show that the problem...
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Accelerated impedance spectrum measurement via multisine perturbationand digital filter banks
PublicationPrzedstawiono przyspieszoną metodę pomiaru widma impedancyjnego, zorientowaną na pomiary jakości powłok przeciwkorozyjnych, modelowanych liniowymi obwodami zastępczymi. Metoda polega na pobudzeniu układu wielosinusoidalnym sygnałem popudzającym oraz analizie pobudzenia i odpowiedzi obiektu przez bank filtrów cyfrowych. Przedstawiono podstawy teoretyczne metody oraz propozycję metodologii pomiaru. Przeanalizowano wyniki symulacji...
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Intracranial electrophysiological recordings from the human brain during memory tasks with pupillometry
PublicationData comprise intracranial EEG (iEEG) brain activity represented by stereo EEG (sEEG) signals, recorded from over 100 electrode channels implanted in any one patient across various brain regions. The iEEG signals were recorded in epilepsy patients (N=10) undergoing invasive monitoring and localization of seizures when they were performing a battery of four memory tasks lasting approx. 1 hour in total. Gaze tracking on the task...
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Identification of sustainable trypsin active‐site inhibitors from Nigrospora sphaerica strain AVA‐1
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Unsteady periodic pressure and capacity for viscoelastic lubrication in spherical hip joint. Nieustalone okresowe ciśnienie i nośność w lepkosprężystym smarowaniu sferycznego stawu biodrowego.
PublicationNiniejsza praca przedstawia obliczenia numeryczne rozkładu wartości ciśnienia i siły nośnej podczas hydrodynamicznego smarowania w szczeliny stawu biodrowego człowieka przy uwzględnieniu okresowego ruchu niestacjonarnego oraz lepkosprężystych właściwości cieczy synowialnej, zmieniających się w czasie. Takie właściwości cieczy synowialnej nie były uwzględniane w dotychczasowych pracach naukowych przy modelowaniu numerycznym stawu...
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Stress analysis in the steel tank shell at its connection with product pipeline
PublicationPrzeanalizowano zaburzenia stanu błonowego w powłoce zbiornika walcowego pionowego w strefie przyłączenia do płaszcza rurociągu produktowego
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NEW APPROACH TO MODELLING SAND FILTER CLOGGING BY SEPTIC TANK EFFLUENT
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Stresses in the zone of process openings in the shell of a vertical cylindrical steel tank
PublicationW dolnej części płaszcza zbiornika walcowego na ciecze konieczne jest wykonanie różnego rodzaju otworów technologicznych. Artykuł poświęcony jest analizie stanu naprężeń w strefie wzmocnień wykonywanych w sąsiedztwie otworów na rurociągi oraz na włazy wyczystkowe w płaszczu zbiornika. Ponieważ charakter zmian naprężeń, a więc i wzmocnień w strefie obu rodzajów otworów jest różny dlatego artykuł podzielony jest na dwie części, z...
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Diagnosis of Damage in a Steel Tank Model by Shaking Table Harmonic Tests
PublicationDiagnosis of damage in civil engineering structures has recently become an important issue in the safety assessment procedure. Among a number of different approaches, a method of measuring the changes in natural frequencies is one of the most effective indicators of global damage. It has been successfully applied to relatively small. structures, however, the tests on large structures are very difficult and the practical application...
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Response of a steel tank during earthquakes and mining tremors - experimental investigation
PublicationCylindrical steel tanks are very popular shell structures used to store the products of chemical and petroleum industries. Any failure might have disastrous consequences, therefore their safety and reliability is essential. Earthquakes are the most dangerous and also the most unpredictable dynamic loads acting on such structures. On the other hand, mining tremors are usually considered to be less severe due to lower acceleration...
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Diagnosis of Damage in a Steel Tank Model by Shaking Table Harmonic Tests
PublicationThe aim of the present paper is to show the results of the shaking table experimental study concerning the diagnosis of damage in a model of cylindrical steel tank with self-supported roof which is filled with liquid. During the tests, the base of the structure was excited under the harmonic loading with variable frequency. The tests were repeated for different stages of damage, which was introduced in the model by easing the bolts...
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Using differential pressure sensor to measure nitrous oxide level in a tank
PublicationA method for measuring the level of liquid nitrous oxide oxidizer in a hybrid rocket motor oxidizer tank is proposed. Presented approach is more accurate than the most commonly used method of this measurement, which employs weighting of the whole sounding rocket or an oxidizer tank. In our solution we use a differential pressure sensor to measure the change of pressure at the bottom of an oxidizer tank in comparison to the pressure...
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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...
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Managing Students’ Affairs at Higher Education Institutions: A Qualitative Analysis of Selected Tasks and Processes
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Chromatic scheduling of 1- and 2-processor uet tasks on dedicated machines with availability constraints.
PublicationRozważono uogólnienie klasycznego szeregowania jednostkowych zadań jedno- i dwuprocesorowych na maszynach dedykowanych. Przyjęty model pozwala na naturalne wprowadzenie wszystkich klasycznych kryteriów optymalizacyjnych dla harmonogramów. Zaproponowano algorytmy wielomianowe dla systemów rzadkich.
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Examining users’ preferences towards vertical graphical toolbars in simple search and point tasks
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Chromatic Scheduling of 1- and 2-Processor UET Tasks on Dedicated Machines with Availability Constraints
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Use of personal knowledge of 8-year-old students in creative solving of technical tasks
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CONSUMERS’ APPROACH TO THE CREDIBILITY OF THE INFLATION FORECASTS PUBLISHED BY CENTRAL BANKS: A NEW METHODOLOGICAL SOLUTION
PublicationModern monetary policy focuses on credibility and shaping inflation expectations. In keeping with the concept of inflation forecast targeting, the inflation forecasts published by central banks play a crucial role in the instrument rate decision-making process and may be treated as a specific intermediate target. This study proposes an inflation forecast credibility index, the scope of which is narrowed to non-specialists’ approach...
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Analyzing content of tasks in Business Process Management. Blending task execution and organization perspectives
PublicationAn efficient organization, management, and execution of tasks are central for the successful functioning of any organization. This topic was on the research agenda already in the early 1950s and keeps attracting the scientific community's attention today. Continuous advances and penetration of technologies in organizations are expected to increase task variety and complexity. This creates a constant demand for new methods to analyze,...
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A multi‑criteria approach to investigate spatial distribution,sources, and the potential toxicological effect of polycyclic aromatic hydrocarbons (PAHs) in sediments of urban retention tanks
PublicationBottom sediments deposited in retention tanks (RTs) located on two urban streams (Oliwski and Strzyza) in the central part of Gdansk (Poland) were analysed for polycyclic aromatic hydrocarbons’ (PAHs) content. PAHs were extracted from samples with methylene chloride, then the extracts were subjected to clean-up applying the solid phase extraction (SPE) method. Quantitative and qualitative determination of 16 PAHs was performed...
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Identification of dynamic parameters in the context of diagnostics of steel tank with different level of liquid.
PublicationThe paper presents an experimental study to identify the dynamic parameters of a water-filled tank model. The experimental modal analysis approach involving the excitation at one point of the structure and acquisition of vibra tions at selected points distri buted over the tank surface allowed to determine the resonance frequencies, mode shapes and damping ratios. The main aim of the research was to examine the influence of...
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Developing Methodology for Model Tests of Floating Platforms in Low -Depth Towing Tank
PublicationThe paper presents two different methods of physical modeling of semi-submersible platform mooring system for research in low depth towing tank. The tested model was made in the scale of 1:100 resembling the "Thunder Horse" platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced starshape and attached at the bottom to suction piles. The tests...
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Diagnosis of Damage in a Steel Tank with Self-Supported Roof through Numerical Analysis
PublicationThe safety of civil engineering structures is one of the most important issues of building industry. That is why the assessment of the damage-involved structural response has recently become of major concern to engineers. Among a number of different approaches to diagnosis of damage, the method of measuring the changes in natural frequencies is considered to be one of the most effective indicators of global damage. From the practical...
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Experimental determination of dynamic properties of cylindrical steel tank model filled with liquid
PublicationIn technical branches, such as chemical or petroleum industries, cylindrical steel tanks are essential structures used for storage of liquid products. Any failure might have disastrous consequences, therefore their safety and reliability is essential. The aim of the present paper is to show the results of the experimental study which has been conducted on a scaled model of a real tank used in Poland. The investigation was carried...
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Developing a methodology for model tests of floating platforms in a towing tank of low depth
PublicationThe paper presents two ways to mooring model of semi-submersible platform for research in the small depth towing pool. The tested model was made in the likeness of 1:100 Thunder Horse platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced Star-shape and attached at the bottom to the suction piles. The tests were performed in the towing pool...
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Probabilistic estimation of diverse soil condition impact on vertical axis tank deformation
PublicationThe calculations of fuel tanks should take into account the geometric imperfections of the structure as well as the variability of the material parameters of the foundation. The deformation of the tank shell can have a significant impact on the limit state of the structure and its operating conditions. The paper presents a probabilistic analysis of a vertical-axis, floating-roof cylindrical shell of a tank with a capacity of 50000...