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Search results for: MEDIUM CARBON STEEL
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Polish small and medium enterprises : chances, barries and challenges
PublicationLata dziewięćdziesiąte przyniosły gospodarce polskiej bardzo szybki wzrost sektora małych i średnich przedsiębiorstw. Jego dynamika miała jednak tendencję gasnącą, szczególnie u progu XXI wieku. Wyjaśnienie przyczyn tych zjawisk może stanowić przesłankę dla oceny bieżącej polityki państwa wobec MSP, a także dla formułowania założeń przyszłej polityki na tym obszarze. Prezentowane opracowanie pokazuje, jak działania państwa w zakresie...
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Cullet As Filter Medium For Swimming Pool Water Treatment
PublicationKontrola jakości wody w basenach kąpielowych może być prowadzona poprzez oczyszczanie wody z uwzględnieniem filtracji i dodawaniemśrodków dezynfekcyjnych. Zanieczyszczenia wody nie zawsze mogą byćskutecznie usuwane przy stosowaniu konwencjonalnych metod uzdatnianiawody. W doświadczeniu zbadano osady powstałe na złożu piaskowym,stwierdzono nieefektywną pracę filtrów piaskowych. Porównano dwazłoża filtracyjne: piasek kwarcowy i...
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Voltage Harmonics Measuring Issues in Medium Voltage Systems
PublicationW rozdziale przedstawiono zagadnienia związane z dokładnością pomiarów zniekształceń harmonicznych napięcia z wykorzystaniem przekładników napięciowych w sieciach średnich napięć.
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Photocatalytic treatment of wastewater generated on small and medium vessels
PublicationW związku z uregulowaniami prawnymi zabronione jest wprowadzanie ścieków szarych z ze statków bezpośrednio do wód morskich. Zanieczyszczenia znajdujące się w tych ściekach muszą być usunięte przed ostatecznym zdeponowaniem. Pozwala na to zastosowanie oczyszczania fotokatalitycznego oraz fotokatalizatorów aktywowanych promieniowaniem z zakresu widzialnego. W artykule przedstawiono pływającą jednostkę badawczą wyposażoną w system...
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Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion
PublicationThe efffciencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been described and analyzed in detail in the paper. Similarly to the Ericsson cycle for gas turbines, isothermal expansion in the turbine is suggested...
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Thin-walled cross section shape influence on steel member resistance.
PublicationThis work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into...
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Failure of austenitic stainless steel tubes during steam generator operation
PublicationThe article presents the failure process of austenitic stainless steels used in power devices, such as heat exchangers, steam generators, in terms of local corrosion: pitting, stress and intergranular corrosion, paying particular attention to welded joints area. The effect of steel chemical composition, microstructure, welding process and work environment was analyzed. The second part of the article presents the results of the...
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NONSTRUCTURAL STIFFNESS ASSESSMENT IN INSTRUMENTED STEEL BUILDINGS
PublicationLateral stiffness of nonstructural components may significantly influence the initial stiffness of the entire structure and consequently alter its dynamic characteristics. While methods for simulating structural members are well-established, approaches for modeling nonstructural components that also participate in seismic response are notably less developed. In this paper a simplified, physically-intuitive approach for estimating...
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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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Photocatalytic Decomposition of Air Pollutants using Electrodeposited Photocatalysts on Stainless Steel
PublicationThe aim of research was to develop an immobilization method for photocatalysts, which is an alternative to the sol-gel or dip coating methods and can be simply scaled up for technical applications. The investigated photocatalyst was TiO2, which was electrochemically deposited onto a cathode made of stainless steel. This deposited film was photocatalytically active. In order to enhance the photoactivity of the TiO2 film, commercially...
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Electrically Conductive Carbon‐based (Bio)‐nanomaterials for Cardiac Tissue Engineering
PublicationA proper self-regenerating capability is lacking in human cardiac tissue which along with the alarming rate of deaths associated with cardiovascular disorders makes tissue engineering critical. Novel approaches are now being investigated in order to speedily overcome the challenges in this path. Tissue engineering has been revolutionized by the advent of nanomaterials, and later by the application of carbon-based nanomaterials...
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Estimation of nonstructural stiffness in instrumented steel frames
PublicationLateral stiffness of nonstructural components may significantly influence the initial stiffness of the entire structure and consequently alter its dynamic characteristics. While methods for simulating structural members are well-established, approaches for modeling nonstructural components that also participate in seismic response are notably less developed. In this paper a simplified, physically-intuitive approach for estimating...
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Electrochemical synthesis and characterization of nanocomposites based on poly(3,4-ethylenedioxythiophene) and functionalized carbon nanotubes
PublicationThis work is focused on new composite materials consisting of poly(3,4-ethylenedioxythiophene) (pEDOT) and functionalized multi-walled carbon nanotubes synthesized electrochemically. Three types of composites were synthesized: the first one containing carbon nanotubes with carboxyl groups (covalent functionalization), the second one containing oxidized carbon nanotubes ox-MWCNTs (with different oxygen-rich polar groups) (covalent...
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EXPERIMENTAL STUDY OF A TEMPORARY STEEL GRANDSTAND UNDER CROWD LOAD
PublicationTemporary structures, such as grandstands, are commonly used during different types of mass events, especially sport and music concerts. In this paper, the results of the experimental study on temporary steel grandstand are presented. The aim of the investigation was to determine modal characteristics of such structures. Modes of free vibrations and corresponding natural frequencies have been obtained for empty and occupied grandstand....
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Biomass-Derived Nitrogen Functionalized Carbon Nanodots and Their Anti-Biofouling Properties
PublicationThe prevalence of the antibiotic resistant bacteria remains a global issue. Cheap, sustainable and multifunctional antibacterial membranes are at the forefront of filtrating materials capable of treating multiple flow streams, such as water cleansing treatments. Carbon nanomaterials are particularly interesting objects shown to enhance antibacterial properties of composite materials. In this article, amino-functionalized, photoluminescent...
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Investigation of polyurethane elastomer–steel joints using glass lacquer as an adhesive agent
PublicationThis article describes an innovative method of coupling polyurethane elastomer (based on polyurethane glycolysate) with constructional steel, by implementation of a Glaspur®—glass lacquer containing latent polyurethanes and monosilane adhesion promoters. The commonly applied coupling agent is Cilbond® 45SF glue or its derivatives. Additionally, glycolysate was synthesised from polyurethane waste and 1,3-propylene glycol in 6:1...
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VIBRATION PROBLEMS OF AN EXAMPLE OF TEMPORARY STEEL GRANDSTAND UNDER HUMAN-INDUCED EXCITATION
PublicationLighter and slender structural members of a typical grandstand leads to a significant reduction in the frequencies, that is why such structures are more easily induced to vibrations. The aim of the present paper is to show the results of our experimental studies and the numerical analyses, focused on the behaviour of a part of a typical temporary steel grandstand under dynamic loads. The peak values of accelerations of a steel...
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Experimental study on the effectiveness of polymer damper in damage reduction of temporary steel grandstand
PublicationA large number of accidents, involving collapses of temporary grandstands during different types of events, were observed in the past. If the synchronized movement of people is tuned with the natural frequency of the affected part of the structure, resonance might occur. It may lead to severe damages of grandstands, their collapse or panic among the spectators. The aim of the paper is to assess, through preliminary experimental...
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Synergistic effects of nitrogen-doped carbon and praseodymium oxide in electrochemical water splitting
PublicationHybrid materials featuring perovskite-type metal oxide in conjunction with heteroatom-doped graphene hold immense promise as alternatives to costly noble metal catalysts for electrochemical water splitting, facilitating the generation of environmentally friendly hydrogen. In this study, perovskite-type oxide containing praseodymium, barium, strontium, cobalt, and iron atoms dispersed in a carbon matrix as a catalyst is synthesized...
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A DFT+U study of carbon nanotubes under influence of a gate voltage
PublicationA possibility of appearance of antiferromagnetic ordering in armchair carbon nanotubes and graphene is studied using density functional theory within a DFT+U approach. It is shown that the Coulomb repulsion between electrons in the -orbitals of graphene would need to reach a threshold value of ,...
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Passive sampling as a tool for obtaining reliable analyticalinformation in environmental quality monitoring
PublicationSpośród technik pobierania próbek analitów technika dozymetrii pasywnej wydaje się być interesującą alternatywą w stosunku do powszechnie stosowanych technik dynamicznych. Dozymetria pasywna łączy w sobie etap pobierania próbki z etapem izolacji i wzbogacania analitów, które są zatrzymywane w odpowiednim medium zatrzymującym. Prowadzi to do znacznego uproszczenia operacji analitycznych wykonywanych in situ. W odróżnieniu od aktywnych...
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Dynamics of fault arc traveling along busbars in high voltage switchboards = Dynamika łuku zwarciowego przemieszczającego się wzdłuż szyn rozdziel-nic wysokiego napięcia
PublicationThe paper presents the results of magnetic induction and electrodynamic force calculations acting on arc column during short-circuit in medium voltage air-insulated bus-bars. The gap between the bars was 120 mm and the prospective short-circuit currents ranged from 4 kA to 8 kA. The paper also shows the measurement results of average velocity fault arc depending on currents arc diameter and arc current was established and described....
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Układ sterowania pracą próżniowego kolektora słonecznego do grzania powietrza
PublicationZastąpienie w kolektorze słonecznym medium ogrzewanego z wody na powietrze pozwala na uzyskanie wysokiej temperatury powietrza wewnątrz kolektora oraz poprzez pominięcie czynnika pośredniego na zwiększenie wydajności kolektora. Dzięki temu możliwy jest ciągły obieg powietrza bez konieczności oczekiwania na podgrzanie, co ma miejsce przy podgrzewaniu wody. Rozwiązanie takie może być stosowane do grzania pomieszczeń w miesiącach...
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Endoscopic image processing and analysis of pistons' service failures of marine diesel engines
PublicationThe paper deals with diagnostic issues concerning endoscopic examinations of working spaces within marine diesel engines. In the beginning, endoscopy apparatus being on laboratory equipment of the Department of Ship Power Plants of Gdansk University of Technology has been characterized. The endoscopy considerations have been focused on theoretical bases of a digital image processing and especially - on the "Shadow" measurement...
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Zmiany wybranych parametrów fizykochemicznych olejów oliwkowych i oleju rzepakowego w czasie procesu smażenia w cienkiej warstwie
PublicationBadano zmiany wybranych wyróżników jakości oleju w zależności od czasu ogrzewania i rodzaju użytego tłuszczu, podczas modelowego smażenia w cienkiej warstwie tłuszczu. Oznaczanymi wyróżnikami były: LK, LOO, LAn, nD40, zawartość frakcji polarnej oraz ilość dimerów i polimerów TAG. Jako medium smażalnicze stosowano różne rodzaje olejów oliwkowych (Extra virgin, pomace, sansa) oraz olej rzepakowy.Stwierdzono, że tempo przemian termooksydatywnych...
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Analysis of the harmonic structure of the vowel /a/ taking into account the age and gender of the speaker
PublicationSound waves are disturbances propagating through an elastic medium that, upon reaching the ear, elicit auditory sensations. Sounds generated by the surroundings can be captured by a transducer (microphone), which transforms them into an electrical signal. The signal from the microphone is then transmitted to a computer, where software allows for the extraction and analysis of individual tones. This process enables the description...
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Wykorzystanie światłowodów w przemyśle elektroenergetycznym
PublicationAktualnie, eksploatacja czujników światłowodowych w elektroenergetyce nie jest rozwiązaniem powszechnie stosowanym, jednak wykorzystanie włókien światłowodowych w rozległych systemach sterowania i nadzoru, jakim jest np. Krajowy System Elektroenergetyczny, jest już standardem. Połączenie transmisji światłowodowej z techniką cyfrową wpłynęło na niezawodność łączy technologicznych, co spowodowało wzrost niezawodności i bezpieczeństwa...
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Hydraulic conductivity of a biopolymer treated sand
PublicationThis paper presents results of laboratory assessment of creating seepage barriers in a sandy soil using biopolymer additives (bio substance), which consist of polysaccharides and water. Polysaccharides strongly interact with water to produce a viscous suspension. The aim of the conducted work was to investigate the influence of a biosubstance employed in a highly permeable sandy soil. The amount of the biopolymer used in a sample...
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Self-Association of Amphotericin B: Spontaneous Formation of Molecular Structures Responsible for the Toxic Side Effects of the Antibiotic
PublicationAmphotericin B (AmB) is a lifesaving antibiotic used to treat deep-seated mycotic infections. Both the pharmaceutical activity and highly toxic side effects of the drug rely on its interaction with biomembranes, which is governed by the molecular organization of AmB. In the present work we present detailed analysis of self-assembly of AmB molecules in different environments, interesting from the physiological standpoint, based...
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Examples of numerical simulations of two-dimensional unsaturated flow with VS2DI code using different interblock conductivity averaging schemes
PublicationFlow in unsaturated porous media is commonly described by the Richards equation. This equation is strongly nonlinear due to interrelationships between water pressure head (negative in unsaturated conditions), water content and hydraulic conductivity. The accuracy of numerical solution of the Richards equation often depends on the method used to estimate average hydraulic conductivity between neighboring nodes or cells of the numerical...
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IDEA SMART CITY W KONTEKŚCIE ROZWOJU PRZEDSIĘBIORCZOŚCI NA PRZEDMIEŚCIACH
PublicationSmart City Concept in the Context of Enterpreneurship Development in Suburban Areas. Supporting innovation and knowledge within economic development, these are the goals of public managers, enthusiasts of the Smart City concept. It is questioned whether this concept is the best solution for regional development and efficient support to local entrepreneurship based on SMEs (small and medium enterprises). Moreover, the results of...
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Dynamic Research of Masonry Vault in a Technical Scale
PublicationThe paper presents preliminary results of dynamic tests of the masonry barrel vault in a technical scale. Experimental studies are intended to identify material properties of homogenized masonry vaults under dynamic loads. The aim of the work is to create numerical models to analyse vault’s dynamic response to dynamic loads in a simplest and accurate way. The process of building the vault in a technical scale is presented in the...
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New RFID readers for scalable RFID system
PublicationRFID systems gives the opportunity to have wide access control integrated with the monitoring of people and goods flow. System's scalability is one of the most important features in such systems as they enable large scale deployments. The concept of the proposed reader's architecture employs new RFID transceivers and microcontrollers, security algorithms which gives very high functionality at low price. Special treatment of system's...
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Monitoring and analytics of semivolatile organic compounds (SVOCs) in indoor air
PublicationThis paper reviews literature information on the behaviour of semivolatile organic compounds (SVOCs) in the indoor environment, as well as the most likely emission sources. The consecutive stages of analytical procedures used for monitoring SVOCs in indoor environments are described. The most common approaches used for collecting samples from the gas and particulate phases are mentioned. The paper discusses and compares various...
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The effects of offshoring to low-wage countries on domestic wages: a worldwide industrial analysis
PublicationThis paper extends the literature on the implications of offshoring for labour markets by investigating its effect on the wages of different skill groups in a broad global context. The analysis draws on input–output data from the WIOD project, and in the panel analysed (13 manufacturing industries, 40 countries, 1995–2009) we account for up to 96 % of the international trade in manufacturing inputs. Being particularly interested...
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Fiber-optic sensors based on microspheres with nanocoatings (Zastosowanie mikrosfer optycznych z cienkowarstwowymi pokryciami w czujnikach światłowodowych)
PublicationTemperature is one of the most important physical quantities. Temperature measurements are used in every field of life, especially electronics, electrical engineering, energy-related fields, including energy source and storage devices. The goal of this dissertation is to design and optimize the microsphere-based fiber-optic sensors construction for measurement of the sensor surrounding medium temperature, including selection of...
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Simulations of the Derecho Event in Poland of 11th August 2017 Using WRF Model
PublicationThis series contains datasets related to the forecasting of a severe weather event, a derecho, in Poland on 11 August 2017. The simulations were conducted using the Weather Research and Forecasting (WRF) model version 4.2.1 with different initial and boundary conditions of the pressure and model levels derived from 5 global models: Global Forecast System (GFS), Global Data Assimilation System (GDAS), European Centre for Medium-Range...
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A new tool for the evaluation of the analytical procedure: Green Analytical Procedure Index
PublicationA new means for assessing analytical protocols relating to green analytical chemistry attributes has been developed. The new tool, called GAPI (Green Analytical Procedure Index), evaluates the green character of an entire analytical methodology, from sample collection to final determination, and was created using such tools as the National Environmental Methods Index (NEMI) or Analytical Eco-Scale to provide not only general but...
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Tire/Road Noise On Poroelastic Road Surfaces - Results Of Laboratory Measurements
PublicationTire/road noise is the most important part of traffic noise for medium and high speed driving both in the case of passenger cars and trucks. The potential to make modification of tires that significantly reduce tire/road noise in nearly over, at least for conventional tires so the only promising action is to improve road pavements. One of the innovative solutions is poroelastic road pavement (PERS) that reduces airflow related...
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Nanolayers in Fiber-Optic Biosensing
PublicationIn this chapter, fiber-optic sensors based on nanolayers or thin films and their ability to perform biophotonic measurements is presented. In the last decade, fiber-optic sensors have gained popularity as biosensing devices. This has been made possible because of the design and the integration of new materials in fiber-optic technology. Nanolayers and thin films made from various materials such as nanodiamond (NCD), boron-doped...
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Właściwości i sterowanie próżniowego kolektora słonecznego do grzania poowietrza
PublicationZastąpienie w kolektorze słonecznym medium ogrzewanego z wody na powietrze pozwala na uzyskanie wysokiej temperatury powietrza wewnątrz kolektora oraz poprzez pominięcie czynnika pośredniego na zwiększenie wydajności kolektora. Dzięki temu możliwy jest ciągły obieg powietrza bez konieczności oczekiwania na podgrzanie, co ma miejsce przy podgrzewaniu wody. Rozwiązanie takie może być stosowane do grzania pomieszczeń w miesiącach...
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Influence of type of material on performance of hydraulic components in thermal shock conditions
PublicationDuring the start-up of a hydraulic system in low ambient temperatures an incorrect operation may occur. The principles and conditions of safely operating hydraulic driven machines and devices are essential to designers and operators. For this reason the author of this article has conducted a series of tests on hydraulic components and systems in thermal shock conditions (cooled-down components were supplied with hot working medium)....
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Signal Propagation in Electromagnetic Media Modelled by the Two-Sided Fractional Derivative
PublicationIn this paper, wave propagation is considered in a medium described by a fractional-order model, which is formulated with the use of the two-sided fractional derivative of Ortigueira and Machado. Although the relation of the derivative to causality is clearly specified in its definition, there is no obvious relation between causality of the derivative and causality of the transfer function induced by this derivative. Hence, causality...
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Application of advanced spectroscopic methods in the assessment of the leachability degree of hazardous elements from the matrix of cellular concretea
PublicationDue to its structure, autoclaved cellular concrete exhibits good insulating properties with relatively high compressive strength values. It is increasingly used in construction because of its economic attractiveness. Autoclaved cellular concrete is mainly used in interior structure layers, and therefore its potential exposure to heavy metal leaching from the matrix may be related to the presence of a high pH medium from other materials...
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The influence of global climate change on the environmental fate of anthropogenic pollution released from the permafrost
PublicationThis article presents a review of information related to the influence of potential permafrost degradation on the environmental fate of chemical species which are relased and stored, classified as potential influence in future Antarctic environment. Considering all data regarding climate change prediction, this topic may prove important issue for the future state of the Antarctic environment. A detailed survey on soil and permafrost...
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Local material symmetry group for first- and second-order strain gradient fluids
PublicationUsing an unified approach based on the local material symmetry group introduced for general first- and second-order strain gradient elastic media, we analyze the constitutive equations of strain gradient fluids. For the strain gradient medium there exists a strain energy density dependent on first- and higher-order gradients of placement vector, whereas for fluids a strain energy depends on a current mass density and its gradients....
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Failures and a concept of corrosion protection system for spiral classifiers at KGHM Polska Miedź S.A. Ore Concentration Plant
PublicationThe Ore Concentration Plant, where the process of flotation is carried out as well as the final production of copper concentrate, plays a key role in the entire production line of KGHM Polska Miedź S.A. Majority of operations related to the run-of-mine preparation to copper flotation enrichment are carried out in a water environment. The maintaining of production process continuity requires to pursue minimisation of many production...
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On the production of electricity in Poland using a geothermal binary power plant - A thermodynamic overview - Part I
PublicationPoland has a significant potential of geothermal energy. However, the high-temperature sources that are needed to drive power plants are found in relatively few places. Therefore, the objective of this paper is to consider any location in the northern part of Poland as a possible place to build a binary power plant. A scientific research was confirmed the existence of an elevated temperature gradient in this region. The hot rocks...
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Implementing Smart Virtual Product Development (SVPD) to Support Product Manufacturing
PublicationThis paper illustrates the concept of providing the manufacturing knowledge during early stages of product life cycle to experts working on product development. The aim of this research is to enable a more collaborative product development environment by using Smart Virtual Product Development (SVPD) system, which is powered by Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). It enhances the industrial product...
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Strength parameters of deltaic soils determined with CPTU, DMT and FVT
PublicationThis paper presents the results of soil investigation in soft, normally consolidated organic soil in the estuary of Vistula river. The analysis concerns clayey mud and peat layers interbedded with loose to medium-dense sands. Several Cone Penetration Tests with pore water measurement (CPTU), Dilatometer Tests (DMT) and Field Vane Tests (FVT) were performed on the testing site. The cone factor Nkt was estimated using the results...