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River flow simulation based on the HEC-RAS system
PublikacjaThis work considers the problem of river floods, and presents a computer solution that can be used to predict such a threat. The basic tool, called Hydrologic Engineering Centers for River Analysis System (HEC-RAS), and created by the US Army Corps of Engineering, is well developed; and the models created in the system HEC-RAS are quite realistic. For the purpose of solving practical national flood problems, simplified static and...
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River Flow Simulation Based on the HEC-RAS System
PublikacjaThis work considers the problem of river floods, and presents a computer solution that can be used to predict such a threat. The basic tool, called Hydrologic Engineering Centers for River Analysis System (HEC-RAS), and created by the US Army Corps of Engineering, is well developed; and the models created in the system HEC-RAS are quite realistic. For the purpose of solving practical national flood problems, simplified static and...
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Mutagenic and Carcinogenic Compounds in Food
PublikacjaFood is a major environmental human cancer risk factor. One of the reasons for this is that food products contain substances that exhibit mutagenic and carcinogenic potential which may induce the transformation of normal somatic cells into cancerous cells. These compounds occur in food as a result of microbial contaminations (mycotoxins produced by molds), are generated from natural food components upon processing (e.g. heterocyclic...
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Water Footprint Assessment of Selected Polymers, Polymer Blends, Composites, and Biocomposites for Industrial Application
PublikacjaThis paper presents a water footprint assessment of polymers, polymer blends, composites, and biocomposites based on a standardized EUR-pallet case study. The water footprint analysis is based on life cycle assessment (LCA). The study investigates six variants of EUR-pallet production depending on the materials used. The system boundary included the production of each material and the injection molding to obtain a standardized...
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Ireneusz Kreja dr hab. inż.
OsobyAbsolwent klasy matematycznej I Liceum Ogólnokształcącego w Gdańsku im. Mikołaja Kopernika (1974). Absolwent Wydziału Budownictwa Lądowego Politechniki Gdańskiej (1979). Od 1979 pracuje na PG. W 1989 uzyskał doktorat (z wyróżnieniem), na Wydziale Budownictwa Lądowego, a w 2008 habilitował się (również z wyróżnieniem) na Wydziale Inżynierii Lądowej i Środowiska PG. Od 2011 jest profesorem PG. Na Politechnice Gdańskiej pełnił funkcje:...
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Ocena stanu technicznego rurociągu przesyłowego zawiesiny popiołów w Elektrowni Ostrołęka B
PublikacjaPrzedmiotem pracy był rurociąg przesyłowy zawiesiny popiołów przesyłanych z Elektrowni Ostrołęka B. Celem pracy było potwierdzenie przynależności próbek yvyciętych z rurociągu do określonego gatunku stali i ocena stanu materiału po eksploatacji. Dla zrealizowania tego celu wykonano: - analizę składu chemicznego materiału pobranego ze stalowych rur, - mikroanalizę warstw wierzchnich na powierzchni wewnętrznej i zewnętrznej, -...
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Modelowanie kratownicy z kształtowników giętych na zimno z mimośrodami dodatnimi w węźle = Modelling of truss with cold-formed section and positive eccentricyty in the node.
PublikacjaThe topic of this research is establishing load-carrying capacity of compressed and tensed chords of trusses made of cold-formed open cross-sections. Occurrence of bending in the truss’ chord is the result of specific production technology assumed by the designer and producer of lattice girder’s systems. The aim of this research is to present methodology of conduct while creating numerical models that best depict the behaviour...
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An Empirical Model for the Polarisation Characteristics of Indoor Off-Body Channels
PublikacjaThis paper presents an analysis of the polarisation characteristics for the channel in dynamic off-body communications, and an empirical channel model, based on measurements performed at 2.45 GHz in an office environment. Body presence and propagation conditions have a strong influence on signal depolarisation. The model assumes three components for the total path loss: mean path loss, represented by a log-distance function with...
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Melody Harmonization with Interpolated Probabilistic Models
PublikacjaMost melody harmonization systems use the generative hidden Markov model (HMM), which model the relation between the hidden chords and the observed melody. Relations to other variables, such as the tonality or the metric structure, are handled by training multiple HMMs or are ignored. In this paper, we propose a discriminative means of combining multiple probabilistic models of various musical variables by means of model interpolation....
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Al-DIAMOND SCHOTTKY TUNNEL DIODES WITH BARRIER HEIGHT CONTROL
PublikacjaFew-nanometer-thick very highly boron-doped p-type layers were fabricated at metal-semiconductor interfaces of Schottky barrier diodes formed with aluminum on polycrystalline diamond. Preliminary results show that hermionically-assisted tunneling mechanism results in lower voltage drops at forward biasing of these diodes than expected for the Al-diamond metal-semiconductor potential barrier B. The effective barrier height Bpeff...
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Ionization and fragmentation of furan molecules by electron collisions
PublikacjaCation mass spectra obtained by electron impact were measured to investigate the ionization and ionic fragmentation of furan, C4H4O, molecules in the gas phase. The most abundant cations, with comparable intensities in the mass spectra, were the parent, C4H4O+, cation (68 amu) and the C3H3+ fragment (39 amu). The appearance energies of most of the observed ionic fragments were determined and the possible fragmentation processes...
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Modeling of truss with cold-formed section and positive eccentricity in the node
PublikacjaThis work is dedicated to establishing the load carrying capacity of tensed and compressed truss’ nodes made of cold-formed open cross sections. The occurrence of bending in the truss’ nodes is the result of a specific production technology for system lattice girders assumed by the designer and the producer. The aim of this research is to present the methodology of conduct for creation of computational models that best depict the...
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Wideband Off-Body Channel Characteristics with Dynamic User
PublikacjaThis paper presents the preliminary results of a dynamic off-body channel characterisation study, based on wideband measurements at 5.8 GHz in an indoor environment. The Channel Impulse Response (CIR) was measured for a scenario with the user approaching and departing from the off-body antenna. A CIR deconvolution procedure was performed jointly in two polarisations, and the received signal power, Cross-Polarisation Discrimination...
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Quasi-analytical Near-to-Far Field Transformation Based on Field Matching Method for Scattering Problems
PublikacjaA new quasi-analytical near-to-far field transformation based on field matching method (field expansion in a base of Hankel functions) is presented. This approach uses finite element method to obtain near field, then the field is expressed in a base of Hankel functions. The evaluated coefficients allow to calculate the field outside the numerical domain, also in a far distance. The main advantage of the proposed technique is avoiding of...
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Coupled-Resonator Waveguide Filter in Quadruplet Topology With Frequency-Dependent Coupling - A Design Based on Coupling Matrix
PublikacjaThis letter presents an application of a recently developed coupling matrix synthesis technique to design of coupled-resonator filters with dispersive inter-resonator couplings. This technique is used to design a novel coupled-cavity bandpass filter. Measurements validate the design and confirm effectiveness of the synthesis method. The filter is a four-pole generalized Chebyshev filter with three transmission zeros. Resonators...
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Normal stress distribution in built‑up cold‑formed column in relation to interconnecting bolt spacing
PublikacjaIn order to increase a stiffness of cold-formed steel (CFS) elements it is practised to built-up the cross-section. In the analysed case, a main element is strengthened by adding extra chord in contact partially along the column. This additional chord acts as a longitudinal stiffener connected with the main section by series of bolts. Authors check whether rules applied over the years, for hot-rolled elements, can be indiscriminately...
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Investigations on mixture preparation for two phase adiabatic pressure drop of R134a flowing in 5 mm diameter channel
PublikacjaThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a. Study cases have been set for a mass flux varying from 200 to 400 kg/m2 s, at the saturation temperature of 19.4 ◦C. Obtained experimental data was compared with the available correlations from the literature for the frictional pressure drop during adiabatic flow. Influence of mixture preparation on pressure drop was investigated, for...
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Mechanisms of azole resistance among clinical isolates of Candida glabrata in Poland
PublikacjaCandida glabrata is currently ranked as the second most frequently isolated aetiological agent of human fungal infections, next only to Candida albicans. In comparison with C. albicans, C. glabrata shows lower susceptibility to azoles, the most common agents used in treatment of fungal infections. Interestingly, the mechanisms of resistance to azole agents in C. albicans have been much better investigated than those in C. glabrata....
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Ground tire rubber thermo-mechanically devulcanized in the presence of waste engine oil as asphalt modifier
PublikacjaCross-linked elastomers network is main limitation for industrial usage of ground tire rubber (GTR) as asphalts’ and road pavements modifier. GTR was thermo-mechanically devulcanized via extrusion in the presence of waste engine oil (WEO) at temperature ranges from 150 to 280 °C. Combined impact of WEO content and extruder barrel temperature on the change of cross-linked structure of degraded GTR (DTGR) was investigated through...
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Static magnetic multipole susceptibilities of the relativistic hydrogenlike atom in the ground state: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaWe study far- and near-field magnetic and electric multipole moments induced in the ground state of the Dirac one-electron atom placed in a weak 2L-pole magnetostatic field. The analysis is carried out within the framework of the first-order Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian expansion of the generalized Dirac-Coulomb Green function [Szmytkowski, J. Phys. B 30, 825 (1997);J. Phys. B 30, 2747(E)...
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Advancing sustainable hybrid bitumen systems: A compatibilization solution by functionalized polyolefins for enhanced crumb rubber content in bitumen
PublikacjaPolymer waste pollution has a profound effect on the environment and, consequently, on the lifestyle of hu- mankind. The massive production and disposal of cross-linked polymers clearly exemplify the challenges of recycling. Increasing efforts are being undertaken to introduce recycled polymers, especially crumb rubber (CR), into asphalt formulations. Due to the rather poor processability and phase separation associated with CR- modified...
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Load introduction to composite columns revisited—Significance of force allocation and shear connection stiffness
PublikacjaThe AISC 360-16 Specification recommends that the design shear force between parts of a composite column in the load introduction area shall be calculated based on the force allocation at ultimate limit state. Applicability of this straightforward method to the load levels that usually arise in slender composite columns is questionable, as this capacity-based force allocation is only true when the axial force is equal to the plastic...
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One Year Evaluation of Material Properties Changes of Polylactide Parts in Various Hydrolytic Degradation Conditions
PublikacjaBiodegradable biocompatible materials are widely used in medical applications. Determining the possibility of using biodegradable materials depends on determining the changes in their parameters over time due to degradation. The current scientific research on biodegradable materials has presented results based on research methods characterized by the different geometry and cross-section size of the specimen, type of degradation...
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Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations
PublikacjaThe present work focuses on unraveling the collisional processes leading to the fragmentation of the gas-phase furan molecules under the He+ and He2+ cations impact in the energy range 5–2000 eV. The presence of different mechanisms was identified by the analysis of the optical fragmentation spectra measured using the collision-induced emission spectroscopy (CIES) in conjunction with the ab initio calculations. The measurements of...
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The electronic excited states of dichloromethane in the 5.8-10.8 eV energy range investigated by experimental and theoretical methods
PublikacjaWe present a comprehensive experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectrum of dichloromethane, CH 2 Cl 2 , with absolute cross sections determined for the full 5.8–10.8 eV energy-range. The calculations on the vertical excitation energies and oscillator strengths were performed using the equation-of-motion coupled cluster method, restricted to the single and double excitations level (EOM-CCSD), and...
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OPTIMAL FARM SIZE AND EFFECTIVENESS OF AGRICULTURE IN THE EU: THE CASE OF WHEAT YIELDS
PublikacjaThe article concentrates on the relationship between the size of a farm and its efficiency in relation to wheat production in the European Union (EU). The issue is not new, however fundamental from the point of view of the agricultural policy, as the appropriate shape of the agrarian structure affects the economic rationality in agriculture and significantly improves the productivity. We analysed data for the period between 2004...
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Julita Wasilczuk dr hab.
OsobyUrodzona 5 kwietnia 1965 roku w Gdańsku. W latach 1987–1991 odbyła studia na Wydziale Ekonomiki Transportu Uniwersytetu Gdańskiego (obecnie Wydział Ekonomii). Od 1993 roku zatrudniona na nowo utworzonym Wydziale Zarządzania i Ekonomii, Politechniki Gdańskiej, na stanowisku asystenta. W 1997 roku uzyskała stopień doktora nauk ekonomicznych na WZiE, a w 2006 doktora habilitowanego nauk ekonomicznych w dyscyplinie nauki o zarządzaniu,...
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VERSATILE SPACE OF PERSIAN COURT HOUSE IN ISFAHAN USED AS POLISH CHILDREN HABITAT DURING THE WW2
PublikacjaDuring WW2 thousands of Polish citizens were deported to Siberia and Kazakhstan in the USSRdoomed to exterminating labour. The Polish army was also detained there. The Iranian Shahallowed Polish soldiers and civilians to cross from Russia to Iran. In Isfahan Polish fugitives, mainlychildren, were accommodated in Persian traditional court houses which were converted into theirtemporary habitat, where new...
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RSVP-TE as a reservation protocol for optical networks
PublikacjaIn this paper, we consider the reservation of optical resources problem. We implement extensions for RSVP-TE (Resource ReSerVation Protocol with Traffic Engineering Extension) to achieve the new functionality for optical resources reservation. Based on ASON/GMPLS architecture we examine an open source implementation KOM RSVP-Engine and extend its functionality according to ITU-T and IETF recommendations. The transport plane consists...
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What determines export diversification in the development process? Empirical assessment.
PublikacjaThis paper assesses the role played by country-specific factors as determinants of relative export diversification. Using a panel data set for 60 countries and 20 years (1985–2004), we confirm that even after clearing out differences in income per capita, cross-country variability in the degree of export diversification is significant. In general, apart from per capita income, features influencing the size of accessible markets...
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Monitoring of Odour Nuisance from Landfill Using Electronic Nose
PublikacjaThe paper presents the results of investigation on classification of atmospheric air samples collected in a vicinity of municipal landfill with respect to their odour nuisance. The research was conducted using a prototype of electronic nose instrument and a commercial electronic nose of Fast/Flash GC type –HERACLES II. The prototype was equipped with a set of six semiconductor sensors by FIGARO Co.. Classification of the air samples...
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Export Diversification and Development - Empirical Assessment
PublikacjaThis paper assesses the role played by country specific factors as determinants of exports' diversification process. Using a panel data-set for 60 countries and twenty years (1985-2004) we confirm that even after clearing out differences in income per capita, cross section variability in the degree of exports' diversification is significant. In general, apart from per capita income, variables influencing the size of accessible...
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Effect of the inclination angle of the condenser on the heat transfer coefficient value – experimental study
PublikacjaWhen considering problem of the condensation of the refrigerant in a flow inside channel, one needs to pay attention to the shape of its cross-section, the hydraulic diameter, the channel length as well as the orientation of the channel axis in space (horizontal, vertical, inclined). This paper presents an experimental study concerning the effect of the inclination angle of the condenser with a single coil pipe on the heat transfer...
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Numerical modeling of GPR field in damage detection of a reinforced concrete footbridge
PublikacjaThe paper presents a study on the use of the ground penetrating radar (GPR) method in diagnostics of a footbridge. It contains experimental investigations and numerical analyses of the electromagnetic field propagation using the finite difference time domain method (FDTD). The object of research was a reinforced concrete footbridge over a railway line. The calculations of the GPR field propagation were performed on a selected cross-section...
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Influence of water soaking on the ultimate tensile strength of polyester-based coated woven fabrics
PublikacjaThis research aims to determine the influence of water-soaking on polyester-based coated woven fabrics for ultimate tensile strength and elongation at break under uniaxial tensile tests. The paper begins with a short survey of literature concerning the investigation of the determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of a flat grip to establish the values...
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COMPUTER ANALYSIS OF HYDRAULIC CONDITIONS IN A SANITARY CHAMBER
PublikacjaThis paper presents analysis of hydraulic conditions of sewage flow down the slipway (ramp) in the collecting sanitary chamber connecting 3 collectors on the inlet: ⌀600, ⌀800 and ⌀1400 and one on the outlet ⌀1600 mm, with a maximum difference of elevation 5 m. The mathematical model has been made and hydraulic calculations were carried out in steady flow conditions. Then wastewater surface elevation, energy grade line elevation,...
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3D POINT-CLOUD SPATIAL EXPANSION BY TOTAL LEAST-SQUARES LINE FITTING
PublikacjaPoint-cloud spatial expansion (PCSE) allows the creation of a new pointcloud form that presents an alternative geometry of an entire object in a single spatial view. Spatial expansion facilitates the analysis process and introduces an additional spatial parameter describing the point cloud. An important element of the PCSE method is determining the position of the axis of symmetry of a symmetrical object: the procedure for determining...
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HEAT TRANSFER CHARACTERISTICS OF ENHANCED SHELL AND COIL HEAT EXCHANGER
PublikacjaIn the paper authors presented their own constructions of shell and tube heat exchangers with intensified heat transfer. The shell and coils heat exchangers are in common use in heat ventilations and air conditioning systems. Those types of recuperators are quite simple constructions, the low value of pressure drops and good conditions of heat transfer. The present study shows an experimental investigation of the heat transfer...
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Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublikacjaWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
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Lack of control over work and organizational citizenship behavior: overwork climate as a suppressor variable
Dane BadawczeThis study investigates a suppressor effect in the relationship between lack of control over work and organizational citizenship behavior (OCB). Suppressor effects operate when the addition of a predictor (in our study it is an overwork climate) increases the predictive power of another variable (lack of control over work) in predicting an outcome variable...
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Wpływ przechyłki na zjawisko postępowania zużycia bocznego szyn kolejowych w łukach poziomych
PublikacjaDegradacja elementów nawierzchni kolejowej jest zagadnieniem bardzo złożonym, w które uwikłane jest wiele czynników związanych między innymi z układem geometrycznym toru kolejowego, właściwościami trybologicznymi poszczególnych elementów nawierzchni, jak również z parametrami podłoża gruntowego, a także z właściwościami samych pojazdów szynowych. W artykule omówiono jeden z powyższych problemów, tj. wpływ ukształtowania toru kolejowego...
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Rozwój polskiego winiarstwa w latach 2000–2017
PublikacjaW artykule przedstawiono historie polskiego winiarstwa. Na podstawie danych zawartych w raportach Agencji Rynku Rolnego przedstawiono kształtowanie się liczby winnic oraz powierzchni upraw winorośli i zbioru winogron w latach 2009–2018. Dane z portalu winogrodnicy.pl posłużyły do scharakteryzowania liczby winnic wraz z ich lokalizacją oraz powierzchnią. Z przeprowadzonej analizy wynika, że polskie winiarstwo od ponad 20 lat przeżywa...
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Ryszard Jan Barczyński dr hab. inż.
OsobyRyszard Jan Barczyński (ur. 24 czerwca 1957 roku w Gdańsku), polski naukowiec, inżynier, specjalista z dziedziny fizyki ciała stałego i elektronicznych technik pomiarowych. W 1976 roku uzyskał maturę w IV Liceum Ogólnokształcącym im. Tadeusza Kościuszki w Toruniu. Studia wyższe ukończył w 1981 roku w Instytucie Fizyki Politechniki Gdańskiej w specjalności fizyki ciała stałego, uzyskując tytuł zawodowy magistra inżyniera. Od 1981...
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Influence of the addition of citric acid on the physico-chemical properties of poly(sorbitol sebacate-co- butylene sebacate)
PublikacjaThe article presents the results of the physicochemical properties of poly(sorbitol sebacate- co-butylene sebacate) (PSBS) obtained with 0.25; 0.5; 0.75; 1 mol of citric acid (KC). It was shown that PSBS obtained with 0.25 and 0.5 mol KC is characterized by the most optimal mechanical and thermal properties. As a result of the study, it was found that the use of sorbitol and citric acid allows obtaining ester materials with...
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Comparison of Quality Evaluation of Agricultural Distillates Using Prototype of Electronic Nose and Fast/Flash GC
PublikacjaThe paper presents the results of investigation on quality evaluation of agricultural distillates using a prototype of electronic nose instrument and a commercial electronic nose of Fast/Flash GC type – HERACLES II. The prototype was equipped with a set of six semiconductor sensors by FIGARO Co.. In case of the prototype volatile fraction of the agricultural distillate was prepared via barbotage process. HERACLES II analysed the...
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Comparison of different types of electronic nose instruments for evaluation of odour nuisance from landfill
PublikacjaThe paper presents and compares the results of investigation on classification of atmospheric air samples collected in a vicinity of municipal landfill with respect to their odour nuisance. The research was conducted using a prototype of electronic nose instrument and a commercial electronic nose of Fast/Flash GC type – HERACLES II. The prototype was equipped with six semiconductor sensors of TGS type. Classification of the air...
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Torsional buckling and post-buckling of columns made of aluminium alloy
PublikacjaThe paper concerns torsional buckling and the initial post-buckling of axially compressed thin-walled aluminium alloy columns with bisymmetrical cross-section. It is assumed that the column material behaviour is described by the Ramberg–Osgood constitutive equation in non-linear elastic range. The stationary total energy principle is used to derive the governing non-linear differential equation. An approximate solution of the equation...
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Evaluation of the structures size in the liquid-gas flow by gamma-ray absorption
PublikacjaThe rapid development of tomography methods particularly electrical, X and gamma rays allows for a wide range of the information about flow structure. However, all of such methods are quite complicated. At the same time much simpler systems as the measuring system of gamma rays absorption, allows to obtain a all key flow information which describe the two-phase flow. In the article the results of analyzes of radiometric signal...
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Diagnosing marine turbine engines through energy characteristics of their flow section
PublikacjaThe aim of the performed research was to develop of diagnostic method of the flow section of a marine turbine combustion engine based on the level of delamination of its energy characteristics. The here adopted diagnostic model provides for a formulation of the evaluation of the technical conditions based on the measurements of the parameters of the thermodynamic medium in the characteristic control cross-sections of the engine...
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The effects of selected factors on pedestrian crossings in urban areas
PublikacjaPedestrian crossings are designed to help pedestrians cross a road. There are at-grade pedestrian crossings with or without traffic lights and grade separated crossings such as subways and footbridges. Pedestrian crossings may be located next to a junction or on road sections between junctions. Where at-grade crossings are involved, pedestrians and motorists interact, which may lead to dangerous situations and road traffic conflicts....