Search
Filters
total: 1165
filtered: 1023
displaying 1000 best results Help
Search results for: anti-plane waves
-
Acoustic heating produced in resonators filled by a newtonian fluid
PublicationAcoustic heating in resonators is studied. The governing equation of acoustic heating is derived by means of the special linear combination of conservation equations in differential form, allowing the reduction of all acoustic terms in the linear part of the final equation, but preserving terms belonging to the thermal mode responsible for heating. This equation is instantaneous and includes nonlinear acoustic terms that form a...
-
Non-destructive inspection of ground anchors using guided wave propagation
PublicationThis paper deals with numerical and experimental investigations of specific problems of guided wave propagation in ground anchors. The research focuses on recognizing the phenomenon of the energy transfer between anchor components. Particular attention is paid to characteristic features of guided waves propagating in free and embedded parts of the tendon, at the interface between the tendon and the surrounding anchor body as well...
-
Electroelastic biaxial compression of nanoplates considering piezoelectric effects
PublicationIn the present theoretical work, it is assumed that a piezoelectric nanoplate is connected to the voltage meter which voltages have resulted from deformation of the plate due to in-plane compressive forces whether they are critical buckling loads or arbitrary forces. In order to derive governing equations, a simplified four-variable shear deformation plate theory has been employed using Hamilton’s principle and Von-Kármán...
-
Estimation of fracture toughness and shear yield stress of orthotropic materials in cutting with rotating tools
PublicationThe cutting force is an energetic effect of splitting material, and might be considered from a point of view of modern fracture mechanics. Forecasting of the shear plane angle in cutting broaden possibilities for modelling of the cutting process even for thin uncut chips. Such mathematical model has been developed here for description of the orthotropic materials’ cutting on the base of fracture theory, and includes work of separation...
-
Call Control Evaluation in ASON/GMPLS Architecture
PublicationThe Automatically Switched Optical Network (ASON) utilizing Generalized Multi–Protocol Label Switching (GMPLS) protocols named as ASON/GMPLS is one of the propositions of Next Generation Network. The basic assumption of ASON control plane is a separation of call control from connection control. The control plane is divided into call control and connection control components. Presented work regards the problem of call control evaluation...
-
An isogeometric finite element formulation for geometrically exact Timoshenko beams with extensible directors
PublicationAn isogeometric finite element formulation for geometrically and materially nonlinear Timoshenko beams is presented, which incorporates in-plane deformation of the cross-section described by two extensible director vectors. Since those directors belong to the space R3, a configuration can be additively updated. The developed formulation allows direct application of nonlinear three-dimensional constitutive equations without zero...
-
Modelling of shear zones during quasi-static granular silo flow using material point method (MPM)
PublicationThe paper focuses on confined silo flow of cohesionless sand. The problem considered is a quasi-static flow in a plane strain model silo with parallel walls simulated with the material point method (MPM). The simulation used a non-local hypoplastic constitutive model. Initially, the paper validated the implemented numerical approach with basic element tests and a plane strain compression test. The subsequent MPM calculations for...
-
Soiling Effect Mitigation Obtained by Applying Transparent Thin-Films on Solar Panels: Comparison of Different Types of Coatings
PublicationDust accumulation on the front cover of solar panels is closely linked to location and orientation of photovoltaic (PV) installation. Its build-up depends on the module tilt angle, frequency of precipitation, humidity, wind strength and velocity, as well as grain size. Additionally, soil composition is determined by solar farm surroundings such as local factories, agricultural crops, and traffic. Over time, molecules of atmospheric...
-
Usage of Two-Center Basis Function Neural Classifiers in Compact Smart Resistive Sensors
PublicationA new solution of the smart resistance sensorwith the Two-Center Basis Function (TCBF) neuralclassifier, for which the resistance sensor is a component ofan anti-aliasing filter of an ADC is proposed. Thetemperature measurement procedure is based on excitationof the filter by square impulses, sampling time response ofthe filter and processing measured voltage values by theTCBF classifier. All steps of the measurement procedure...
-
Future of medicine: personalized oncology
PublicationUnderstanding genetic and epigenetic mechanisms of tumorigenesis allows identifying many vital mutations affected the formation of various malignancies. This led to the discovery of a new therapeutic approach, based on molecular mechanisms in the world of medicine, which is called personalized medicine (PM). This review aims to outline the state of the art of the personalized medicine in treatment, taking into account anti-cancer...
-
Detection and time/frequency analysis of electric fields in the ground
PublicationThis paper sets out to detect and characterize electric fields in the ground (such as stray current fields) using a tandem time/frequency method of signal analysis. Results were obtained from investigations performed in the presence of a generated electric field with controlled variable characteristics, and in the presence of an electric field generated by a tramline. The analysis of measurement registers was performed using Short‐Time...
-
Localized impedance measurements of AA2024 and AA2024‐T3 performed by means of AFM in contact mode
Publication -
Corrosion resistance evaluation of Al-based alloys by means of dynamic electrochemical impedance spectroscopy
PublicationW pracy przedstawiono wyniki badań stopów aluminium wykonane za pomocą dynamicznej elektrochemicznej spektroskopii. Na podstawie uzyskanych widm impedancyjnych zostały pokazane zmiany parametrów elektrycznego schematu zastępczego z potencjałem. Stwierdzono, że dodatek magnezu do badanego stopu obniża właściwości przeciwkorozyjne stopu.
-
Study of anticorrosion and microwave absprption properties of NiZn ferrite pigments
PublicationPurpose - The purpose of this paper is to report the electrochemical verification of anticorrosive properties of NiZn ferrites as pigments in protective coatings and evaluation of their microwave absorbing properties. Design/methodology/approach - Ferrites, represented by formula NixZn(1-x)Fe2O4, where x=0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a ceramic method. The samples of ferrites were examined by X-ray diffraction...
-
The determination and identification of stray current source influences on buried pipelines using time/frequency analysis
PublicationZaprezentowano metodę detekcji źródła interferencji prądów błądzących na rurociągach podziemnych w aglomeracjach miejskich z wykorzystaniem łącznej analizy czasowo-częstotliwościowej mierzonych sygnałów. Badania przeprowadzono na rurociągu podziemnym zlokalizowanym w sąsiedztwie dwóch trakcji elektrycznych: tramwajowej i kolejowej. Wyniki analiz zaprezentowano w formie spektrogramów, które ilustrują zmiany spektralnej gęstości...
-
Study of anticorrosion and microwave absorption properties of NiZn ferrite pigments
Publication -
The effect of the temperature change rate on determination of the critical pitting temperature of stainless steels
Publication -
The application of Gabor transformation in the harmonic analysis of corrosion processes
Publication -
The impedance method of monitoring the degradation of rubber linings in applications where progressive deterioration is the predominant failure mechanism
Publication -
Durability evaluation of Ni‐Cr‐Mo super alloys in a simulated scrubbed flue gas environment
Publication -
Evaluation and characterisation of the condition of individual components of cathodic protection systems
Publication -
Corrosion resistance evaluation of Al‐based alloys by means of dynamic electrochemical impedance spectroscopy
Publication -
Electrochemical investigations of stainless steels used in flue‐gas desulphurization units
Publication -
The temperature dependencies of susceptibility of 654SMO and 316L stainless steels to pitting
Publication -
AFM-assisted investigation of conformal coatings in electronics
PublicationPurpose – This paper aims to presents a new method of investigation of local properties of conformal coatings utilized in microelectronics. Design/methodology/approach – It is based on atomic force microscopy (AFM) technique supplemented with the ability of local electrical measurements, which apart from topography acquisition allows recording of local impedance spectra, impedance imaging and dc current mapping. Potentialities...
-
Aspects of intergranular corrosion of AISI 321 stainless steel in high-carbon-containing environments
PublicationPurpose – The purpose of this paper is to present a case study of unexpected sensitization to intergranular corrosion of highly resistant AISI 321 steel in petrochemical conditions, where it was subjected to the simultaneous influence of elevated temperature of 250°C and vapors from the asphalt production process. Design/methodology/approach – Corrosion coupons were exposed in an installation carrying asphalt vapors. To identify...
-
Instantaneous impedance evaluation of dissolution of aisi 304 stainless steel during intergranular corrosion
PublicationCelem pracy było uzyskanie informacji dotyczących zróżnicowania parametrów elektrycznych uzyskanych na podstawie zarejestrowanych chwilowych widm impedancyjnych w zakresie aktywacji i reaktywacji roztwarzania wysokostopowej stali austenitycznej AISI podczas postępującego procesu korozji międzykrystalicznej. Badania prowadzono z wykorzystaniem dynamicznej elektrochemicznej spektroskopii impedancyjnej (DEIS). Pomiary wykonywano ''on-line''...
-
Cyclic analysis of thermal impedance of a passive layer of aluminium in a neutral borate buffer solution
PublicationW pracy przedstawiono wyniki badań warstwy pasywnej tworzącej się na stopie 1050 A w warunkach zmieniającej się temperatury. Zmiany realizowano w sposób cykliczny zwiększając a następnie zmniejszając temperaturę. W czasie zmian temperatury prowadzono badania metodę dynamicznej elektrochemicznej spektroskopii impedancyjnej. Stwierdzono największe zmiany parametrów elektrycznego schematu zastępczego w czasie pierwszego cyklu zmian....
-
Studying the effectiveness of a modernized cathodic protection system for an offshore platform
PublicationPrzedstawiono dokonaną modernizację starego systemu ochrony katodowej nóg platformy morskiej oraz omówiono wykonane badania skuteczności przeciwkorozyjnej zastosowanego rozwiązania. Modernizacja polegała na podłączeniu do nóg platformy układów anod galwanicznych umieszczonych na dnie morza. Skuteczność działania systemu oceniono na podstawie pomiarów profili potencjałowych nóg platformy. Po podłączaniu kolejnych układów anod...
-
The effect of the temperature change rate on determination of the criticalpitting temperature of stainless steels
PublicationPrzedstawiono wyniki badań wpływu szybkości zmian temperatury na wyznaczaną krytyczną temperaturę korozji wżerowej. Badania stali 316L przeprowadzono metodą termometrii cyklicznej. Stwierdzono, że zwiększenie szybkości zmian temperatury związane jest ze zwiększeniem wyznaczonej temperatury krytycznej. Zależność krytycznej temperatury korozji wżerowej od szybkości korozji ma charakter liniowy. Wartości krytycznej temperatury korozji...
-
The stationarity characteristics of electrochemical current noise
PublicationPrzedstawiono rezultaty analizy szumu elektrochemicznego generowanego podczas korozji stali 0H18N9 w roztworze 0.1 M H2SO4+0,006 M Cl-. Rejestry uzyskano w warunkach potencjostatycznych. W szumie zaobserwowano trendy i sygnały przejściowe, charakterystyczne dla korozji wżerowej. Trend został usunięty za pomocą aproksymacji wielomianem trzeciego stopnia. Analiza statystyczna wykazała niestacjonarny bądź słabo stacjonarny charakter...
-
Conducting composites as cable anodes in cathodic protection: a literature summary
PublicationPrzedstawiono podstawową charakterystykę systemu ochrony katodowej z wykorzystaniem anod kablowych. Anody kablowe różnią się od klasycznych systemów anodowych sposobem instalacji anod. System anodowy oparty na anodach kablowych nie jest instalowany punktowo; anoda umieszczana jest w niewielkiej odległości od chronionej konstrukcji i biegnie wzdłuż trasy konstrukcji. Materiałem anodowym proponowanego rozwiązania jest elastyczny...
-
The application of Gabor transformation in the harmonic analysis of corrosion processes.
PublicationZaproponowana została nowa metoda analizy widmowej niestacjonarnych procesów korozyjnych. Analizie poddany został układ modelujący pierwszorzędową reakcję elektrodową. Wykazano, że w przypadku pobudzenia układu liniowo zmieniającym się potencjałem z nałożoną składową sinusoidalną przekształcenie Fouriera nie odzwierciedla zmian amplitudy powstających składowych harmonicznych. Jako rozwiązanie zaproponowana została analiza...
-
Potential changes in an electric field and electrolytic corrosion.
PublicationSources have been described of corrosively hazardous electric fields and methods of determination of the corrosion hazard to metal structures caused by electrolytic corrosion. Results of potential and impedance investigations in the field of stray currents flowing out of a tram traction and in the presence of a defined electric field of low frequency have been presented. Uncertainties have been indicated relating to the generally...
-
The protection and monitoring of a distribution piping network for potable water supply
PublicationPurpose – The purpose of this paper is to implement the corrosion protection method for steel pipes used in a municipal water-pipe network. Results of an inhibitor protection system installed on the system are presented. Inhibitor protection was required due to the high corrosivity of the water collected by a surface intake, which had resulted in a large number of failures and low water quality, due to the presence of corrosion...
-
Localized impedance measurements of AA2024 and AA2024-T3 performed by means of AFM in contact mode
PublicationPurpose: The purpose of this paper is to present the results of an atomic force microscopy (AFM) based approach to local impedance spectroscopy (LIS) measurement performed on AA2024 and AA2024-T3 aluminium alloys. Design/methodology/approach: AFM-LIS measurements were performed ex-situ without the electrolyte environment, so in fact the electrical not electrochemical impedance was obtained. Findings: Relative local impedance values...
-
Study of the formation of calcareous deposits on cathodically protected steel in Baltic sea water
PublicationPurpose – The purpose of this paper is to investigate whether the sedimentation of calcareous deposits occurs on cathodically protected steel in Baltic sea water. Design/methodology/approach – Steel electrodes were cathodically polarized in natural Baltic sea water at potential þ0.150 V vs Zn electrode in potentiostatic mode. During exposure chronoamperometric measurements were carried out. After the exposure, the electrode’s surface...
-
Identification of hydroacoustic wave sources of ship in motion
PublicationThis paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In...
-
STUDY OF SEASONAL ACOUSTIC PROPERTIES OF SEA WATER IN SELECTED WATERS OF THE SOUTHERN BALTIC
PublicationClimate Research of the globe is a current task, in particular to confirm the general hypothesis of global warming associated with an increase in average temperature. The sea acoustic climate is derived from the concept of climate and refers to the conditions of propagation of acoustic waves in a particular basin. In this paper, the results of systematic measurements of temperature, salinity and velocity distributions of sound...
-
Yerba Mate - A Long but Current History
PublicationBearing in mind the growing interest in Yerba Mate, a comprehensive study has been prepared containing the most important aspects and possibilities of its use. The introduction of the work contains the species characteristics of Yerba Mate, as well as information about the origin and places of cultivation. The next part focuses on the analysis of the composition, pointing to purine alkaloids, polyphenols, saponins, and minerals...
-
Increasing efficiency of technological process by limiting impact of corrosive environment on operation of spiral classifiers
PublicationMost of the technological operations related to the preparation of the output to be enriched and to the production of the final copper concentrate take place with the use of water environment. Water management, besides using innovative technical and technological solutions, is a significant factor in the whole copper ore enrichment process. Mine water resources and surface water of the tailing pond named "Żelazny Most" are the...
-
A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond
PublicationAccording to the World Health Organization (WHO), almost 2 billion people each year are infected worldwide with flu-like pathogens including influenza. This is a contagious disease caused by viruses belonging to the family Orthomyxoviridae. Employee absenteeism caused by flu infection costs hundreds of millions of dollars every year. To successfully treat influenza virus infections, detection of the virus during the initial development...
-
Chemical Aspects of Biological Activity of Isothiocyanates and Indoles, the Products of Glucosinolate Decomposition
PublicationThere is growing evidence that cancer chemoprevention employing natural, bioactive compounds may halt or at least slow down the different stages of carcinogenesis. A particularly advantageous effect is attributed to derivatives of sulfur-organic phytochemicals, such as glucosinolates (GLs) synthesized mainly in Brassicaceae plant family. GLs are hydrolysed enzymatically to bioactive isothiocyanates (ITC) and indoles, which exhibit strong...
-
SAWING PROCESS AS A NEW ALTERNATIVE WAY OF DETERMINING SOME WOOD PROPERTIES
PublicationCutting forces (power) could be considered from a point of view of modern fracture mechanics. The developed cutting model, derived from fracture mechanics, includes work of separation (fracture toughness) in addition to plasticity and friction, and also dullness of the cutting edge described by the cutting edge radius. Moreover, forecasting of the shear plane angle for the cutting models, broaden possibilities of energetic effects...
-
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...
-
Game with a Purpose for Verification of Mappings Between Wikipedia and WordNet
PublicationThe paper presents a Game with a Purpose for verification of automatically generated mappings focusing on mappings between WordNet synsets and Wikipedia articles. General description of idea standing behind the games with the purpose is given. Description of TGame system, a 2D platform mobile game with verification process included in the game-play, is provided. Additional mechanisms for anti-cheating, increasing player’s motivation...
-
Enhanced-Performance Circularly Polarized MIMO Antenna with Polarization/Pattern Diversity
PublicationDesign of a compact wideband circularly polarized (CP) multiple-input multiple-output (MIMO) antenna with polarization diversity is proposed and characterized for off-body communication. The antenna is based on a simple coplanar waveguide (CPW)-fed monopole extension of the microstrip line. The orthogonal field components required by CP are induced using a simply modified right/left side ground plane. In particular, a stub extending...
-
Comparison of non-linear statical analysis of truss with linear and rotational side supports and 3d roof model
PublicationIn the paper geometrically non-linear analysis of example truss with linear and rotational elastic side supports is compared with geometrically non-linear analysis of part of the roof construction with purlins and truss-bracing. For different stiffness of side-supports a non linear relation between normal force in compressed chord due to out of truss plane displacement has been calculated.
-
Jakość usług w optycznej sieci wielodomenowej z hierarchiczną strukturą płaszczyzn sterowania
PublicationW rozprawie przedstawiono przegląd architektur sieci z gwarancją jakości klas usług oraz stan prac w zakresie realizacji optycznych sieci ASON, GMPLS oraz ASON/GMPLS. Opisano wymagania i zaawansowanie prac w realizacji sieci ASON/GMPLS z hierarchiczną strukturą płaszczyzn sterowania oraz problemy związane z zagadnieniem jakości klas usług w tej sieci. Zaprezentowano założenia, koncepcję oraz realizację modelu symulacyjnego optycznej...
-
Experimental and numerical analysis of wave propagation in ground anchors
PublicationThe article focuses on wave propagation phenomenon in ground anchors. The main aim of the investigation is the non-destructive diagnostics and the assessment of the state of ground anchors, using the guided wave propagation method. Laboratory models of anchors with different lengths of the anchor body were tested and voltage signals of propagating waves were registered at several locations. For all tested specimens corresponding...