Filters
total: 1678
filtered: 1532
displaying 1000 best results Help
Search results for: COMBUSTION PHENOMENON
-
Road texture influence on tyre rolling resistance
PublicationTyre performance, one of the critical factors for vehicle users, is strongly related to theroad surface characteristics, most notably to the pavement texture. Phenomena that occur at the tyre/road interface affect tyre friction (skid resistance), rolling resistance, tyre wear and tyre/road noise. This article deals with relationship between surface texture and rolling resistance of light and heavy vehicle tyres. Mean profile depth...
-
Social Entrepreneurship Avenues for the Field Development through Research Paradigm Intersection Discussion
PublicationThe aim of this paper is to identify and provide key arguments for employing integrative approach in the choice of research paradigm for studying social entrepreneurship phenomenon. The fact that social entrepreneurship as a field of research is at its preliminary stage, serves as argument and gives freedom in the discussion of the choice of employing a research paradigm. The author does so through identifying commonalities and...
-
USEFULNESS OF SEMI-MARKOV PROCESSES AS MODELS OF THE OPERATION PROCESSES FOR MARINE MAIN ENGINES AND OTHER MACHINES OF SHIP POWER PLANTS
PublicationThe paper describes the properties of semi-Markov processes and the opportunities and benefits from their use as models of the operation processes for marine combustion engines and other machines of ship power plants. The emphasis is put on the importance of the theory of semi-Markov processes for development of the theory of marine combustion engines and other machines of ship power plants, as well as for development of the operational...
-
Elementary analysis and energetic potential of the sludge from the Gdynia Dębogórze and Lębork wastewater treatment plants
PublicationThe paper aims to show the results of the elementary analysis of the sewage sludges from wastewater treatment plants in Gdynia Dębogórze and Lębork as well as measurements of the heat of combustion and the calculated calorific values according to regulation PN-93/Z-15008, taking into account water content and the composition of sewage sludge at different utilisation stages. The results presented in this paper are based on the analysis...
-
Nowoczesne metody termochemicznej konwersji biomasy w paliwa gazowe, ciekłe i stałe = Modern methods of thermochemical biomass conversion into gas, liquid and solid fuels
PublicationBiomass utilization through direct- or co-combustion with coal, based on coal, hydrogen and oxygen compounds chemical energy conversion into heat in boilers, is simultaneously the cheapest and - according to experts - economically least effective solution. In case of heat and electricity production in cogeneration process in biomass fueled heat and power stations (wood, straw, energetic plants, RDF etc), investment costs are little...
-
Design and distribution of air nozzles in the biomass boiler assembly
PublicationDue to energy crisis as well as increasing pollution of the environment, renewable energy sources usage increases all over the world. These facts encouraged authors to start research over developing a uniform biomass boiler calculation model. This paper presents a design of biomass boiler assembly created for ORC (Organic Rankine Cycle) unit since these systems could achieve strong position in energy industry....
-
Towards a modification of a regulatory framework aiming at bunker oil spill prevention from ships - A design aspect of bunker tanks vents location guided by CFD simulations
PublicationAlthough accidental bunker oil spills at seaway are relatively rare events, they can be pose real threat to the natural marine environment. One of the reasons for the bunker spill to occur is a design failure; one of the ways it can demonstrate is an improper location or height of vent heads, leading to a bunker oil discharge during heavy rolling, due to sloshing phenomenon. Design of a ship and her systems is guided by various...
-
EMISJA AKUSTYCZNA JAKO SYGNAŁ DIAGNOSTYCZNY ODWZOROWUJĄCY ZMĘCZENIOWE ZUŻYCIE WARSTW ŚLIZGOWYCH PANWI ŁOŻYSK GŁÓWNYCH I KORBOWYCH SILNIKÓW O ZAPŁONIE SAMOCZYNNYM
PublicationW artykule przedstawiono wyniki badań laboratoryjnych, z których wynika, że emisja akustyczna (EA) może być uznana za sygnał diagnostyczny, przydatny do identyfikacji stanu technicznego łożysk głównych i korbowych okrętowych silników o zapłonie samoczynnym. Wykazano w nim bowiem, że parametry emisji akustycznej takie jak: czas rejestracji, energia sygnału, amplituda sygnału, ilość przekroczeń poziomu dyskryminacji, czas narastania,...
-
Diagnostyka eksploatacyjna okrętowych silników spalinowych - tłokowych i turbinowych
PublicationW monografii przedstawiono wybrane zagadnienia diagnostyki technicznej silników spalinowych dużej mocy, zarówno tłokowych, jak i turbinowych, ukierunkowane na eksploatację okrętowych (i nie tylko) systemów energetycznych, w których występują tego typu silniki. W początkowej części opracowania zaproponowano koncepcję systemowego ujęcia diagnostyki eksploatacyjnej silników okrętowych w aspekcie obowiązujących standardów światowych...
-
Carbon dioxide potential reduction using Start-Stop system in a car
PublicationOperating fuel consumption increases significantly when the vehicle stops frequently while driving or when the engine is idling during braking. In such cases, the internal combustion engine consumes the fuel but the mechanical energy is not used by the drive system. The amount of fuel that is consumed in this time by the engine can potentially be saved if the car is equipped with a Stop-Start system. Start-Stop system automatically...
-
WYBRANE WŁAŚCIWOŚCI FIZYCZNO-CHEMICZNE MIKROSFER I MOŻLIWOŚĆ ICH WYKORZYSTANIA W KOMPOZYTACH CEMENTOWYCH : The selected physico-chemical properties of microspheres and possibility of their use in cement composites
PublicationMicrospheres are formed during the mineral transformation stage in coal combustion. Their content in fly ashes from the combustion of different types of coals varies over a rather wide range from 0.01 to 4.8 wt.%. The microspheres have three main elements, silicon, aluminum and iron, the oxides of which account for about 89.0 wt.% of the material. Mineralogical analysis using XRD shows that microspheres mainly contain mullite and...
-
Dimethyl ether (DME) as potential environmental friendly fuel
PublicationIn recent years, there has been a growing interest in replacing petroleum fuels with so-called second generation environmental friendly fuels. Compared to traditional petroleum fuels dimethyl ether (DME) could be used as a clean high-efficiency compression ignition fuel with reduced particulate matter (PM), sulfur oxides (SOx), hydrocarbons (HC), carbon monoxide (CO) as well as combustion noise. Compared to some of the other leading...
-
Influence of the air phase on water flow in dikes
PublicationNumerical models are often used to describe flow and deformation processes occurring in dikes during flood events. Modeling of such phenomena is a challenging task, due to the complexity of the system, consisting of three material phases: soil skeleton, pore water and pore air. Additional difficulties are transient loading caused by variable in time water levels, heterogeneity of the soil or air...
-
How high-tech solutions support the fight against IUU and ghost fishing: a review of innovative approaches, methods, and trends
PublicationIllegal, Unreported, and Unregulated fishing is a major threat to human food supply and marine ecosystem health. Not only is it a cause of significant economic loss but also its effects have serious long-term environmental implications, such as overfishing and ocean pollution. The beginning of the fight against this problem dates since the early 2000s. From that time, a number of approaches and methods have been developed and reported....
-
Water-mediated influence of a crowded environment on internal vibrations of a protein molecule
PublicationThe influence of crowding on the protein inner dynamics is examined by putting a single protein molecule close to one or two neighboring protein molecules. The presence of additional molecules influences the amplitudes of protein fluctuations. Also, a weak dynamical coupling of collective velocities of surface atoms of proteins separated by a layer of water is detected. The possible mechanisms of these phenomena are described....
-
Using UAV Photogrammetry to Analyse Changes in the Coastal Zone Based on the Sopot Tombolo (Salient) Measurement Project
PublicationThe main factors influencing the shape of the beach, shoreline and seabed include undulation, wind and coastal currents. These phenomena cause continuous and multidimensional changes in the shape of the seabed and the Earth’s surface, and when they occur in an area of intense human activity, they should be constantly monitored. In 2018 and 2019, several measurement campaigns took place in the littoral zone in Sopot, related to...
-
Selected Problems of Cogeneration Energy Systems Designing, Fueled with Landfill Biogas
PublicationThe article discusses the impact of the quality of biogas fuel for operation of generating sets with internal combustion engines. There are presented selected investigation results of landfill biogas fueled gensets operation. The article includes also discussion of the possibility of increasing the efficiency of biogas fuelled cogeneration systems. It also presents guidelines for the optimal design of landfill biogas fueled engines,...
-
Pronouncement of embedded agency in the field of social entrepreneurship
PublicationThe paper provides insights into how social entrepreneurship and the institutional theory framework can be combined. The author situates the social entrepreneurship phenomenon here, and embarks on the traditional structure vs agency debate from social sciences, sociology of organizations in particular. The concept of embedded agency is referred to and employed to explain the phenomenon of social entrepreneurship. In this paper,...
-
The (over)touristification of European historic cities: a relation between urban heritage and short-term rental market demand
PublicationIn this chapter, I wish to highlight the critical relationship between heritage management issues and building environment transformation. I argue that such a relationship is directly expressed through the tourism phenomenon, and it should be measured through the economic dimension of the short-term rental market, which introduces this rule of thumb: if there is a lack of demand, the brand of the city is weak; if there is too much...
-
Ordinal pattern statistics for the assessment of heart rate variability
PublicationThe recognition of all main features of a healthy heart rhythm (the so-called sinus rhythm) is still one of the biggest challenges in contemporary cardiology. Recently the interesting physiological phenomenon of heart rate asymmetry has been observed. This phenomenon is related to unbalanced contributions of heart rate decelerations and accelerations to heart rate variability. In this paper we apply methods based on the concept...
-
The Implementation of the Taxonomic Spatial Measure of Development in the Analysis of Convergence in the Standard of Living
PublicationThe main goal of this paper is to analyse the existence of the social convergence in the European Union between 19952012. The social convergence refers to a reduction in the dispersion of the standard of living across countries. A taxonomic spatial measure of development was used as the standard of living approximation. The use of the new approach proposed by E. Antczak allowed for an explanation of the disparities in the analysed...
-
The Caustic in the Acoustics of Historic Interiors
PublicationIn the paper, caustics are discussed as ordered forms of focus broadening occurring in concave mirrors. Presented are examples of caustics formed in natural conditions and application of the phenomenon in different fields of science and technology. Against this factual background, the possibility to observe caustics in rooms is pointed out. Special emphasis is put on large rooms of historic character, as such interiors frequently...
-
On the Use of Selected 4th Generation Nuclear Reactors in Marine Power Plants
PublicationThis article provides a review of the possibility of using different types of reactors to power ships. The analyses were carried out for three different large vessels: a container ship, a liquid gas carrier and a bulk carrier. A novelty of this work is the analysis of the proposal to adapt marine power plants to ecological requirements in shipping by replacing the conventional propulsion system based on internal combustion engines...
-
The evaluation of the vibration measurement usability of electronic indicator lemag "premet C"
PublicationThe measuring possibilities of modern compression and combustion pressure analyzers are extended with additional functions. One of them is parallel to the pressure measurement, the measurement of vibrations in the region of the cylinder head. The paper presents a general assessment of the vibration measurement function of the electronic indicator LEMAG "PREMET C". This feature is very rarely offered by manufacturers of these devices....
-
Redefiniowanie przestrzeni medycznej = Redefining healthcare space
PublicationSzpital jest obiektem publicznym, budynkiem-miastem, jego architektura nakierowana jest na realizację procesu leczenia i zdrowienia, a jednocześnie formuje przestrzenne ramy mikrokosmosu interakcji społecznych rozgrywających się pomiędzy pacjentami i personelem, gośćmi i „mieszkańcami”. Współcześnie w podejściu do rozumienia czym jest szpital - a zatem również do kształtowania architektury obiektów medycznych - można zauważyć dwa...
-
Możliwości zamiany elektrycznych przepływomierzy powietrza stosowanych w silnikach spalinowych samochodów
PublicationW artykule przedstawiono podstawowe typy przepływomierzy powietrza, stosowane w silnikach spalinowych samochodów: z klapąspiętrzającą, HLM, HFM, Vortex i MAP. Przedstawiono wyniki badania tych przepływomierzy na specjalnie przygotowanym stanowisku pomiarowym. Przeanalizowano możliwość ich zamiany i zweryfikowano taką możliwość w praktyce.
-
An asymmetrical λ-foot of condensing steam flow in the IMP PAN nozzle
PublicationIn the present paper we have focused on the precise prediction of the spontaneous condensation phenomena in wet steam flow. Novelty of our approach lies on modelling both the moment of initiation of a phase transition, as well as the moment of its reverse progress - called here re-vaporization of the condensate phase. The practical issue is to elaborate of a model of spontaneous condensation/vaporization of water steam flow...
-
Mussel‐inspired biomaterials: From chemistry to clinic
PublicationAfter several billions of years, nature still makes decisions on its own to identify, develop, and direct the most effective material for phenomena/challenges faced. Likewise, and inspired by the nature, we learned how to take steps in developing new technologies and materials innovations. Wet and strong adhesion by Mytilidae mussels (among which Mytilus edulis—blue mussel and Mytilus californianus—California mussel are the most...
-
Metropolitan dimension of Tri-City: Development of the new harbor structures
PublicationThis article deals with the phenomenon of urban waterfront transformation. The special focus is on the Tri-City area in Poland. Both the transformation of port structures and redevelopment of the post-harbor areas are presented.
-
Spectral Methods for Modelling of Wave Propagation in Structures in Terms of Damage Detection—A Review
PublicationModern methods of detection and identification of structural damage direct the activities of scientific groups towards the improvement of diagnostic methods using for example the phenomenon of mechanical wave propagation. Damage detection methods that use mechanical wave propagation in structural components are extremely effective. Many different numerical approaches are used to model this phenomenon, but, due to their universal...
-
Tworzenie wartości dla akcjonariuszy w świetle nadzoru korporacyjnego
PublicationDuży odsetek spółek publicznych w Polsce nie tworzy wartości dla akcjonariuszy. Zaprezento-wano wyniki badań dotyczących wpływu struktur własności na efektywność działania spółek pu-blicznych. Badania te nie były w stanie wyjaśnić w wystarczającym stopniu zjawiska destrukcji warto-ści. Starano się wykazać, że jedną z przyczyn tego zjawiska jest transfer wartości. Zalicza się go do głównych problemów nadzoru korporacyjnego. Szczególna...
-
Selected Issues of Hybrid Outboard Motors
PublicationThe aim of the research reported in the article was designing a hybrid drive system based on an outboard internal combustion engine offered by a selected producer and testing its operating characteristics. The article presents different designs of this type of drive which can be found in the literature and are available in the market. The designed hybrid outboard drive system was tested both on the laboratory test rig and in real...
-
Feasibility of combined diesel engine - steam turbine in power station operating in the maritime
PublicationCompression-ignition engines used in ship technology as main propulsion engines are large units reaching even to 50-60 MW. Currently, the efficiency of such engines amounts to 45-50%. With such a large power unit, exhaust gases leaving the engine contain very large quantities of heat available for further treatment. Exhaust gases from the piston engine contain about 25% of the heat supplied to the engine in the fuel. Using the...
-
Application of Thermo-chemical Technologies for Conversion of Associated Gas in Diesel-Gas Turbine Installations for Oil and Gas Floating Units
PublicationThe paper considers the issue of thermo-chemical recovery of engine’s waste heat and its further use for steam conversion of the associated gas for oil and gas floating units. The characteristics of the associated gas are presented, and problems of its application in dual-fuel medium-speed internal combustion engines are discussed. Various variants of combined diesel-gas turbine power plant with thermo-chemical heat recovery are...
-
Thermal utilization of meat-and-bone meal using the rotary kiln pyrolyzer and the fluidized bed boiler – The performance of pilot-scale installation
PublicationThermal utilization of meat-and-bone meal (MBM) is subject to stringent regulations that are meant to provide elimination of any potential pathogens. Incineration as well as other possible routes for thermal conversion of MBM are still at the research state. The universal technology was developed that allows to combust various types of waste organic materials, including animal waste, municipal solid waste and sludge, mixed at any...
-
Decreasing CO2 Emissions By Reducing Tire Rolling Resistance
PublicationThe first motor vehicle was built by Nicolas Cugnot almost 250 years ago and since then there has been a continuous process of motor vehicles’ improvements, as well as development of new road pavements. The fuel crisis of the 70s of the 20th century made it clear to vehicle builders that measures should be taken to reduce vehicle fuel consumption and it contributed to an increased interest in electric vehicles. Although significant...
-
ASSESSMENT OF ENGINE OPERATION WITH THE USE OF AN OPERATION INDICATOR BASED ON TEST BENCH RESULTS OF A ROBINSUBARU EX17 ENGINE
PublicationPaper presents results of an experimental verification of the method of quantitative evaluation of engine operation, presented in the literature, exemplified by a low-power internal combustion piston engine. In accordance with such interpretation, engine operation may be presented as a physical quantity defined as operation indicator. The paper presents results of preliminary tests, processed in that aspect, carried out on an engine...
-
Superadditivity of two quantum information resources
PublicationEntanglement is one of the most puzzling features of quantum theory and a principal resource for quantum information processing. It is well known that in classical information theory, the addition of two classical information resources will not lead to any extra advantages. On the contrary, in quantum information, a spectacular phenomenon of the superadditivity of two quantum information resources emerges. It shows that quantum...
-
Corporate Entrepreneurship: A Literature Review and Future Research Perspectives
PublicationBackground. Nowadays, corporate entrepreneurship (CE) is perceived as an essential approach to boost the innovation and creativity within existing organizations for achieving higher opportunities in the market. This paper examines this concept, which has been largely discussed in the Anglo-Saxon world over the last thirty years. Like for many other phenomena, also in case of CE, this discussion has provided numerous conceptualizations,...
-
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...
-
Innovative Turbine Intake Air Cooling Systems and Their Rational Designing
PublicationThe improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the...
-
An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea
PublicationIn this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and...
-
Pilot installation for thermal utilization of meat-and-bone meal using the rotary kiln pyrolyzer and the fluidised bed boiler
PublicationThe technology of thermal utilization of meat-and-bone meal (MBM) is still at the research state. However, there are already a number of existing pilot-scale installations that provide the complete, effective and environmentally safe process conducting. The universal technology was developed that allows to combust various types of waste, including animal waste, municipal waste and sludge, mixed at any ratio with different types...
-
Analytics of airport runoff water samples
PublicationThe everyday activities at airports, such as aircraft and ground vehicle washing, cleaning, de/anti-icing operations, fuelling, and fuel combustion, removing weeds are the main sources of airport industrial wastes. Runoff waters from airport areas constitute a serious environmental problem as they contribute to air, water, and soil pollution. The paper supplies general information on the technologies for treating airport runoff...
-
Legal destructive entrepreneurship in the modern economy
PublicationMotivation: Usually examples of activities that have a positive impact on the economy of the state are cited. Destructive entrepreneurship refers to activities that have negative impact on the economy. This phenomenon is relatively new in the literature and does not yet have a precise definition. Aim: The aim of this article is to attempt a definition of the phenomenon of legal destructive entrepreneurship. The author also analysed...
-
Tradycyjna versus przyspieszona internacjonalizacja przedsiębiorstw z branż high-tech. Wyniki badań empirycznych
PublicationThe discussion on the role and importance of time in the process of internationalization of firms belongs to the mainstream of research in the field of internationalization. In the literature, the phenomenon of early and rapid internationalization was noticed in the early 1980s; however, the intensive development of the research into this phenomenon began a decade later and continues today. For several years in Poland, the share...
-
Application of bioassays in studies on the impact of pharmaceuticals on the environment
PublicationDrug interactions are often desirable particularly in medicine, when treatment of a patient requires using a mixture of drugs in specific doses to produce the adequate therapeutic effect. Unfortunately, interactions between drugs in the environment are not as desirable, despite the fact that drugs are present in the environment at low concentration levels [1]. Pharmaceuticals are present in the environment in a mixture of compounds,...
-
Study of a Flame Kernel Evolution in a Turbulent Mixing Layer Using LES with a Laminar Chemistry Model
Publication -
Critical conditions of hydrogen-air detonation in partially confined geometry
Publication -
Modelling of two-component turbulent mass and heat transfer in air-fed pressurised suits
PublicationIn this paper the modelling of an important industrial problem is addressed, which involves the two-component turbulent flow with heat transfer that takes place inside protective clothing. The geometry of the flow boundaries is reconstructed in a CAD system from photogrammetry scan data. The overall model is sufficiently realistic to allow, after validation, design improvements to be tested. Those presented here allow the reduction...