Wyszukiwarka
Wydział Inżynierii Mechanicznej i Okrętownictwa
Publikacje
Filtry
wszystkich: 2602
wyświetlamy 1000 najlepszych wyników Pomoc
Katalog Publikacji
Rok 2021
-
METODY IDENTYFIKACJI STANÓW NIEZDATNOŚCI EKSPLOATACYJNEJ ŁOŻYSK TOCZNYCH W OKRĘTOWYCH UKŁADACH NAPĘDOWYCH Z WYKORZYSTANIEM METODY IMPULSÓW UDAROWYCH
PublikacjaRozpatrując okrętowe zespoły napędowe z punktu widzenia transmisji energii mechanicznej największym zagrożeniem dla ich niezawodności jest utrata stabilności układu mechanicznego, co zazwyczaj objawia się zwiększeniem amplitudy drgań mechanicznych. Zwiększeniu tych drgań towarzyszy wzrost amplitudy okresowo zmiennych naprężeń wewnętrznych co jest prostą i nieuniknioną drogą do uszkodzenia znajdujących się w tym układzie łożysk....
-
Microstructure and mechanical properties of laser surface-treated Ti13nb13zr alloy with MWCNTs coatings
PublikacjaLaser surface modification of titanium alloys is one of the main methods of improving the properties of titanium alloys used in implantology. This study investigates the microstructural morphology of a laser-modified surface layer on a Ti13Nb13Zr alloy with and without a carbon nanotube coating deposited by electrophoretic deposition. Laser modification was performed for samples with and without carbon nanotube coating for two...
-
Microstructure and Properties of Electroless Ni-P/Si3N4 Nanocomposite Coatings Deposited on the AW-7075 Aluminum Alloy
PublikacjaThe article presents the results of mechanical and tribological tests of Ni-P/Si3N4 nanocomposite coatings deposited on the AW-7075 aluminum alloy using the chemical reduction method. The influence of the chemical composition on the Vickers microhardness determined by the DSI method was examined. The nanocomposite layers were made of Si3N4 silicon nitride in a polydisperse powder with a particle size ranging from 20 to 25 nm. The...
-
Moda jako wartość konsumencka - eksplikacja zagadnienia
PublikacjaCel: Celem artykułu jest przedstawienie problematyki mody jako propozycji wartości dla klienta. Realizacja niniejszego celu wymagała uszczegółowionej eksplikacji zjawiska mody. W publikacji zdefiniowaniu poddano mechanizm działania mody, istotę trendu mody, jak również omówiono główne perspektywy analizy mody oraz aktualne nurty badań nad modą. Projekt badania/metodyka badawcza/koncepcja: W pracy wykorzystano metodę krytycznej...
-
MODERNIZACJA DYDAKTYCZNEGO STANOWISKA LABORATORYJNEGO UMOŻLIWIAJĄCEGO ANALIZĘ PORÓWNAWCZĄ SPRAWNOŚCI ŚRUB NAPĘDOWYCH JACHTU MOTOROWEGO
PublikacjaW artykule przedstawiono autorską metodę wyznaczania sprawności działania różnych śrub napędowych jachtu motorowego na podstawie wyników badań wykonanych na zmodernizowanym stanowisku laboratoryjnym. Modernizacja stanowiska składającego się ze źródła mocy w postaci silnika elektrycznego, części pośredniczącej i pędnika polegała na dodaniu przetwornika częstotliwości umożliwiającego starowanie silnikiem elektrycznym, czujnika do...
-
Modyfikacja cementu kostnego w celu uzyskania długotrwałej ochrony antybakteryjnej
PublikacjaNiniejsza rozprawa doktorska stanowi przewodnik po jednotematycznym cyklu publikacji, dotyczącym modyfikacji akrylowego cementu kostnego celem uzyskania długotrwałej i efektywnej ochrony antybakteryjnej. W ramach niego przeprowadzono badania eksperymentalne polegające na opracowaniu technologii wytwarzania modyfikowanego cementu kostnego oraz procedury medycznej jego stosowania. Cement kostny był modyfikowany przez zastosowanie...
-
Multiaxial fatigue behaviour of maraging steel produced by selective laser melting
Publikacja -
Neural Modelling of Steam Turbine Control Stage
PublikacjaThe paper describes possibility of steam turbine control stage neural model creation. It is of great importance because wider application of green energy causes severe conditions for control of energy generation systems operation Results of chosen steam turbine of 200 MW power measurements are applied as an example showing way of neural model creation. They serve as training and testing data of such neural model. Relatively simple...
-
Optimisation and field assessment of poroelastic wearing course bond quality
PublikacjaCompared to typical asphalt mixtures, poroelastic mixtures are characterised by high porosity and high flexibility, which are desirable for traffic noise reduction. However, the same properties increase the risk of debonding from the lower layer, which is a significant source of premature damage. The study investigates which of the factors – tack coat agent, type and texture of the lower layer – have the greatest impact on interlayer...
-
OPTIMIZATION OF THE LAST STAGE OF GAS-STEAM TURBINE USING A HYBRID METHOD
PublikacjaThis paper relates to the CFD calculation of a new turbine type which is in the phase of theoretical analysis, because the working fluid is a mixture of steam and gas generated in wet combustion chamber. At first, this article concentrates on a possibility of streamlining the flow efficiency of a last stage of axial turbine working on gas-steam mixture using a hybrid of the particle swarm optimization algorithm with the Nelder-Mead...
-
Perfect thermal contact of hyperbolic conduction semispaces with an interfacial heat source
PublikacjaThe problem of thermal contact between two bodies with a heat source at their interface presents great scientific and practical interest. On the time scale of a nanosecond or shorter, heat propagation should be considered in the form of thermal waves of finite speeds. This study investigated the thermal behaviour of hyperbolic conduction semispaces in perfect thermal contact subjected to the action of an interfacial heat source....
-
Performance and Emission Modelling and Simulation of Marine Diesel Engines using Publicly Available Engine Data
PublikacjaTo analyse the behaviour of marine diesel engines in unsteady states for different purposes, for example to determine the fuel consumption or emissions level, to adjust the control strategy, to manage the maintenance, etc., a goal-based mathematical model that can be easily implemented for simulation is necessary. Such a model usually requires a wide range of operating data, measured on a test stand. This is a time-consuming process...
-
Performance of acicular grindable thermocouples for temperature measurements at sliding contacts
PublikacjaThe present study investigates the performance of acicular grindable thermocouples based on a constantan wire / steel hollow cylinder construction. The experiments showed that the measuring junction electrical resistance, temperature–voltage characteristic, measuring junction rise time and signal noise standard deviation of the acicular thermocouples are comparable to those of conventional J-type thermocouples with bare wire diameter...
-
Planning optimised multi-tasking operations under the capability for parallel machining
PublikacjaThe advent of advanced multi-tasking machines (MTMs) in the metalworking industry has provided the opportunity for more efficient parallel machining as compared to traditional sequential processing. It entailed the need for developing appropriate reasoning schemes for efficient process planning to take advantage of machining capabilities inherent in these machines. This paper addresses an adequate methodical approach for a non-linear...
-
PROJEKT STANOWISKA DYDAKTYCZNEGO DO WYZNACZANIA CHARAKTERYSTYK POMP WIROWYCH
PublikacjaW artykule przedstawiono projekt oraz gotowe stanowisko do wyznaczenia charakterystyk przepływowych pomp wirowych w pracy indywidualnej oraz w wybranych wariantach współpracy szeregowej jak i równoległej. Obserwację parametrów kontrolnych pomp wirowych w różnych stanach pracy: dławienie przepływu, zmiana prędkości obrotowej. Dużą zaletą stanowiska jest wymuszanie obserwację zjawiska kawitacji.
-
Quasistatic and fatigue behavior of an AISI H13 steel obtained by additive manufacturing and conventional method
Publikacja -
Recent Advances in Loop Heat Pipes with Flat Evaporator
PublikacjaThe focus of this review is to present the current advances in Loop Heat Pipes (LHP) with flat evaporators, which address the current challenges to the wide implementation of the technology. A recent advance in LHP is the design of flat-shaped evaporators, which is better suited to the geometry of discretely mounted electronics components (microprocessors) and therefore negate the need for an additional transfer surface (saddle)...
-
Research and applications of active bearings: A state-of-the-art review
Publikacja -
Research and applications of active bearings: A state-of-the-art review
PublikacjaControllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly...
-
Role of cholesterol in substrate recognition by -secretase
Publikacja-Secretase is an enzyme known to cleave multiple substrates within their transmembrane domains, with the amyloid precursor protein of Alzheimer’s Disease among the most prominent examples. The activity of -secretase strictly depends on the membrane cholesterol content, yet the mechanistic role of cholesterol in the substrate binding and cleavage remains unclear. In this work, we used all-atom molecular dynamics simulations to examine...
-
Selected Aspects of Pavement Texture Influence on Tire Rolling Resistance
PublikacjaTire rolling resistance has a significant influence on fuel consumption in cars and trucks and on CO2 emissions. Rolling resistance depends on the tire construction, pavement texture and stiffness, as well as environmental and traffic conditions. This article presents a pilot study on the impact of pavement texture on the rolling resistance of passenger car tires. Reasons why Mean Profile Depth is not a good descriptor of pavement...
-
Selected manufacturing difficulties encountered during setup of machining on cnc multi-axis linear automatic lathe and on cnc multi-spindle turning centers
PublikacjaThe article presents the observed manufacturing technology implementation difficulties in workshop practice, resulting from the construction and principles of operation on the DMG’s SPRINT 32/5 CNC linear automatic lathe and on the Mazak’s HQR 150 MSY and QTN 200 MS CNC turn - mill centers, and discusses possible rules for solving the production problems encountered. The article also discusses the principles of dividing the machining...
-
Self-assembly, stability and conductance of amphotericin B channels: bridging the gap between structure and function
PublikacjaAmphotericin B (AmB), one of the most powerful but also toxic drugs used to treat systemic mycoses, is believed to selectively permeabilize fungal cell membranes to ions in a sterol-dependent manner. Unfortunately, the structure of the biologically active AmB channels has long eluded researchers, obstructing the design of safer alternatives. Here, we investigate the structural and thermodynamic aspects of channel formation, stability,...
-
Special Issue "Applications of Finite Element Modeling for Mechanical and Mechatronic Systems"
PublikacjaNumerical modeling is very important in today's engineering because, among other things, it reduces the costs associated with prototyping or predicting the occurrence of potentially dangerous situations during operation in certain defined conditions. Different methods have so far been used to implement the real structure into the numerical version. The most popular have been variations of the finite element method (FEM). The aim...
-
SPECTRAL RESPONSE OF STATIONARY JACK-UP PLATFORMS LOADED BY SEA WAVES AND WIND USING PERTURBATION METHOD
PublikacjaThe paper addresses non-linear vibrations of offshore jack-up drilling platforms loaded by sea waves and wind in their stationary condition using the perturbation method. Non-linearity of dynamic equations of motion for fixed offshore platforms yields from two factors. The first is load excitation generating non-linear velocity coupling in a dynamic system. This coupling is inherent in the modified Morison equation, involving the...
-
Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
Publikacja -
STUDY ON THE RELATIONSHIP BETWEEN VEHICLE MAINTENANCE AND FUEL CONSUMPTION
PublikacjaA contemporary road vehicle (RV) is a rather complex system, consisting of a large number of subsystems, assemblies, units, and elements (parts). While operating, an RV interacts with the environment, and its elements interact with each other. Consequently, the properties (parameters) of these elements change in the process - hardness, roughness, size, relative position, gapping, etc. A partial solution to the presented problems...
-
TEST METHOD FOR DETERMINING THE CHEMICAL EMISSIONS OF A MARINE DIESEL ENGINE EXHAUST IN OPERATION
PublikacjaThe article briefly describes the problem of air pollution caused by sea-going ships and the resulting restrictions on the emission of toxic and harmful chemical compounds in the exhaust of marine engines, introduced by the International Maritime Organization (IMO) under the International Convention for the Prevention of Sea Pollution from Ships (MARPOL 73/78). Such emissions provide a significant metrological problem, not only...
-
The concept of suspended urban rail vehicle
PublikacjaNiniejsza publikacja została poświęcona szczegółowemu opisowi proponowanej przez autorów koncepcji podwieszanego pojazdu szynowego. W pierwszej kolejności przeanalizowano istniejące rozwiązania, wraz ze wskazaniem ich podstawowych wad i zalet. Następnie opisano proponowaną konstrukcję w zakresie: budowy wagonu, sposobu jego zawieszenia oraz prowadzenia po zadanym torze ruchu. Artykuł ten powstał na podstawie pracy dyplomowej pt....
-
The construction of suspended rail vehicle bogie
PublikacjaNiniejsza publikacja została poświęcona szczegółowemu opisowi wózka, przeznaczonego do wykorzystania w proponowanej przez autorów koncepcji podwieszanego pojazdu szynowego. W pierwszej kolejności skrótowo opisano rzeczony pojazd, ze szczególnym naciskiem na parametry determinujące konstrukcję wózków. Następnie zostały omówione zastosowane rozwiązania konstrukcyjne w zakresie budowy poszczególnych podzespołów wózka, takich jak: zestawy...
-
The crack surface morphology investigation of S355J2 steel after bending-torsion fatigue
Publikacja -
The Development of a Combined Method to Quickly Assess Ship Speed and Fuel Consumption at Different Powertrain Load and Sea Conditions
PublikacjaDecision 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...
-
The effect of Fe on chemical stability and oxygen evolution performance of high surface area SrTix-1FexO3-δ mixed ionic-electronic conductors in alkaline media
PublikacjaDevelopment of environmentally friendly, high performing oxygen evolution reaction (OER) catalysts is an important research challenge. In this work, iron doped strontium titanates with a general formula SrTi1-xFexO3-δ (x = 0.35, 0.50, 0.70, 0.90, and 1.00) denoted as STFx, were synthesized via a solid state reaction technique and characterized in terms of oxygen evolution reaction electrocatalysis in an alkaline electrolyte (0.1...
-
The Influence of External Additional Loading on the Muscle Activity and Ground Reaction Forces during Gait
PublikacjaAsymmetrical external loading acting on the usculoskeletal system is generally considered unhealthy. Despite this knowledge, carrying loads in an asymmetrical manner like carrying on one shoulder, with one hand, or on the strap across the torso is a common practice. This study is aimed at presenting the effects of the mentioned load carrying methods on muscle activity assessed by using thermal field and ground reaction forces....
-
The Influence of Loop Heat Pipe Evaporator Porous Structure Parameters and Charge on Its Effectiveness for Ethanol and Water as Working Fluids
PublikacjaAbstract: This paper presents the results of experiments carried out on a specially designed experimental rig designed for the study of capillary pressure generated in the Loop Heat Pipe (LHP) evaporator. The commercially available porous structure made of sintered stainless steel constitutes the wick. Three different geometries of the porous wicks were tested, featuring the pore radius of 1, 3 and 7 um. Ethanol and water as two...
-
The Matter of Decision-Making Control Over Operation Processes of Marine Power Plant Systems with the Use of their Models in the form of Semi-Markov Decision-Making Processes
PublikacjaThe article presents the possibility to control the real operation process of an arbitrary device installed in the marine power plant based on the four-state semi-Markov process, being the model of the process, which describes the transition process of operational states of the device and the transition process of its technical states. All these states are precisely defined for the ship main engine (SG). A hypothesis is proposed...
-
The Staged Combustion of Meat-and-Bone Meal:The Characteristics of Conversion Sub-processes and Large-Scale Process Outputs
Publikacjat Organic waste has been playing an increasingly important role in the energy market as those that may support the economies in pursuing towards decarbonization by increasing the share of renewables in the overall energy balance. In this group of alternative fuels, meat-and-bone meals being a post-production waste of the steadily developing meat industry, constitute a considerable proportion. Though they are rich in minerals, their...
-
Towards a Framework of Operational-Risk Assessment for a Maritime Autonomous Surface Ship
Publikacja -
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
PublikacjaAlthough 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...
-
Ultimate strength of stiffened plates subjected to compressive load and spatially distributed mechanical properties
PublikacjaThe present study deals with the ultimate strength of stiffened plates subjected to spatially distributed mechanical properties and compressive load. Normally, mean values of mechanical properties based on tensile tests are used to validate the numerical assessment with experimental results. However, mechanical properties may vary within a single specimen. To investigate the impact of that, random fields of yield stress and Young...
-
Wpływ parametrów zewnętrznych na wytwarzanie pary w kotle opalanym
PublikacjaW artykule przedstawiono analizę statystyczną wpływu parametrów zewnętrznych na strumień ciepła zawartego w paliwie dolotowym do okrętowego kotła opalanego. Jako parametry niezależne wytypowano średnią dobową moc chwilową silnika głównego i agregatów prądotwórczych, temperaturę wody zaburtowej oraz zanurzenie. Analizę przeprowadzono dla czterech różnych stanów eksploatacyjnych badanego statku.
-
ZASTOSOWANIE STATYSTYKI F ROZKŁADU FISHERA-SNEDECORA DO OCENY ISTOTNOŚCI WPŁYWU ZMIAN STOPNIA KOMPRESJI SILNIKA O ZS NA ŚREDNIĄ WARTOŚĆ MIĘDZYSZCZYTOWĄ TEMPERATURY SPALIN WYLOTOWYCH
PublikacjaW artykule omówiono wpływ zmian stopnia kompresji na parametry pracy silnika o ZS, m.in. na temperaturę spalin wylotowych. Przedstawiono budowę stanowiska laboratoryjnego, na którym przeprowadzono badania eksperymentalne. Scharakteryzowano, w jaki sposób w istniejącym silniku wprowadzano faktyczne zmiany stopnia kompresji. Zaprezentowano program badań eksperymentalnych uwzględniający dostępne stanowisko badawcze i jego możliwości...
Rok 2020
-
A modelling approach to the transport support for the harvesting and transportation complex under uncertain conditions
PublikacjaThe article proposes a modelling approach based on structural and parametric identification of the transport support of the harvesting and transportation complex. The efficiency and effectiveness of the proposed methods of structural and parametric identification for the development of a system for harvesting and transportation complex operation has been proved. A mathematical model based on fuzzy logic has been developed. It reflects...
-
A Population-Based Method with Selection of a Search Operator
PublikacjaThis paper presents a method based on a population in which the parameters of individuals can be processed by operators from various population-based algorithms. The mechanism of selecting operators is based on the introduction of an additional binary parameters vector located in each individual, on the basis of which it is decided which operators are to be used to modify individuals’ parameters. Thus, in the proposed approach,...
-
Absolute Photoabsorption Cross-Sections of Methanol for Terrestrial and Astrophysical Relevance
PublikacjaWe investigate the methanol absorption spectrum in the range 5.5–10.8 eV to provide accurate and absolute cross-sections values. The main goal of this study is to provide a comprehensive analysis of methanol electronic-state spectroscopy by employing high-resolution vacuum ultraviolet (VUV) photoabsorption measurements together with state-of-the-art quantum chemical calculation methods. The VUV spectrum reveals several new features...
-
An enhanced method in predicting tensile behaviour of corroded thick steel plate specimens by using random field approach
PublikacjaThe present work investigates the possibility of using random field techniques in modelling the mechanical behaviour of corroded thick steel plate specimens. The nonlinear Finite Element method, employing the explicit dynamic solver, is used to analyse the mechanical properties of typical specimens. A material model considering full nonlinearity is used to evaluate the stress-strain response. The influence of major governing parameters...
-
Analiza doboru parametrów pogłębiarki ssącej nasiębiernej
PublikacjaArtykuł przedstawia analizę doboru parametrów pogłębiarek ssących nasiębiernych. Do najważniejszych parametrów charakteryzujących pogłębiarki ssące nasiębierne należą pojemność ładowni gruntowej, prędkość pływania pogłębiarki oraz parametry instalacji pogłębiarskiej. Zaproponowano w analizie doboru tych parametrów zmienność kilku zmiennych ściśle związanych z doborem pogłębiarki, jest to czas załadunku i rozładunku oraz czas trwania...
-
ANALIZA PRZEBIEGÓW ZMIAN TEMPERATURY CZYNNIKA ROBOCZEGO W CYLINDRZE ORAZ KANALE SPALIN WYLOTOWYCH SILNIKA O ZS DLA POTRZEB DIAGNOSTYCZNYCH - STAN BADAŃ
PublikacjaCharakter przebiegów zmian ciśnienia i temperatury czynnika roboczego w silniku o zapłonie samoczynnym jest istotnym źródłem informacji diagnostycznych. Pozwalają na analizę stanu technicznego zarówno aparatury paliwowej jak i układu cieplno - przepływowego. Dotyczy to zarówno temperatury i ciśnienia gazów w czasie całego cyklu pracy silnika o ZS wewnątrz cylindra, jak i tych samych parametrów dotyczących spalin, rejestrowanych...
-
Analysis of hull, propeller and engine interactions in regular waves by a combination of experiment and simulation
PublikacjaAnalysis of hull, propeller and engine interactions in regular waves by a combination of experiment and simulation
-
Analysis of Modal Parameters Using a Statistical Approach for Condition Monitoring of the Wind Turbine Blade
PublikacjaThe primary objective of the presented paper is the numerical and experimental investigation related to developing a useful diagnostic method, which can be used for determining the site and size of damage in laminated shells of wind turbine blades. The described detection technique is based on the analysis of low frequencies bending vibrations mode shapes of rotor blades. The authors used the commonly applied statistics methods...