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Wyniki wyszukiwania dla: permeation passive samplers
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Experimental and Computational Fluid Dynamics Studies on Straight and U-Bend Double Tube Heat Exchangers with Active and Passive Enhancement Methods
PublikacjaIn this work, the authors wanted to demonstrate the possibility to increase the heat transfer efficiency by using simple wire coil inserts to create turbulent flow in the boundary layer as well as air blowing into the annulus of the pipe. Experimental investigations were carried out for four heat exchanger constructions, i.e., plain double tube, turbulized double tube, plain U-bend double tube, U-tube with turbulator, plain double...
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Zastosowanie techniki dozymetrii pasywnej do oceny jakości powietrza wewnętrznego. Application of passive sampling technique for assessment of indoor air quality
PublikacjaJakość powietrza wewnętrznego jest istotnym parametrem wpływającym na dobre samopoczucie i zdrowie człowieka. Kluczowego znaczenia nabiera więc jego nieustanna kontrola i oznaczanie zawartości zanieczyszczeń, które występują w nim na bardzo niskich poziomach stężeń. Do pomiarów jakości powietrza wewnętrznego często wykorzystywana jest (znana od ponad pół wieku) technika dozymetrii pasywnej. W literaturze nadal pojawiają się doniesienia...
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Adrian Bekasiewicz dr hab. inż.
OsobyAdrian Bekasiewicz received the MSc, PhD, and DSc degrees in electronic engineering from Gdansk University of Technology, Poland, in 2011, 2016, and 2020, respectively. In 2014, he joined Engineering Optimization & Modeling Center where he held a Research Associate and a Postdoctoral Fellow positions, respectively. Currently, he is an Associate Professor with Gdansk University of Technology, Poland. His research interests include...
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Levels of hemoglobin and lipid peroxidation metabolites in blood, catalase activity in erythrocytes and peak expiratory flow rate in subjects with passive exposure to tobacco smoke
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Analysis of electrochemical parameters in time domain during the passive layer cracking occurring on the 304L stainless steel in chlorides solution under tensile stresses
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Analysis of electrochemical parameters in time domain during the passive layer cracking occurring on the 304L stainless steel in chlorides solution under tensile stresses.
PublikacjaDynamiczna Elektrochemiczna Spektroskopia Impedancyjna została wykorzystana do szczegółowej analizy zakresu przejścia stan pasywny - stan aktywny podczas procesu pękania warstwy pasywnej. Wpływ potencjału oraz naprężeń mechanicznych na niszczenie warstwy ochronnej występującej na stali 304L w środowisku 0.5M NaCl w pokojowej temperaturze został przestudiowany. Praca prezentuje chwilowe widma impedancyjne uzyskane przy różnych warunkach...
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Recent advances of selected passive heat transfer intensification methods for phase change material-based latent heat energy storage units: A review
PublikacjaThe following article overviews recent studies regarding heat transfer enhancement methods, explicitly focusing on fins and coils utilization, in phase change material-based latent heat thermal energy storage systems. It discusses the influence of various geometrical and material parameters on the melting and solidification processes, as well as the orientation of the heat transfer surface within the storage tank. Additionally,...
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The effect of strain rate on the passive layer cracking of 304L stainless steel in chloride solutions based on the differential analysis of electrochemical parameters obtained by means of DEIS
PublikacjaOkreślono wpływ szybkości rozciągania w zakresie 10-5s-1 ÷ 16∙10-5s-1 na niestacjonarny proces elektrochemiczny pękania warstwy pasywnej. Badania przeprowadzono na stali wysokostopowej 304L w temperaturze pokojowej w środowisku chlorków za pomocą dynamicznej elektrochemicznej spektroskopii impedancyjnej (DEIS). W rezultacie uzyskano zestaw chwilowych widm impedancyjnych odzwierciedlających dynamikę badanego układu korozyjnego....
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Investigations of quasi-static vortex structures in 2D sand specimen under passive earth pressure conditions based on DEM and Helmholtz-Hodge vector field decomposition.
PublikacjaArtykuł przedstawia wyniki obliczeń quasi-statycznych struktur wirowych w 2-wymiarowej próbce piasku w warunkach pasywnego parcia gruntu. Zastosowano metodę elementów dyskretnych i dekompozycję Helmholtza-Hodge’a pola wektorowego. Stwierdzono bliską zależność między wirami a miejscem powstania strefy lokalizacji odkształceń stycznych.
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Passive sampling techniques in monitoring of BTEX in urban air = Technika dozymetrii pasywnej w monitoringu analitów z grupy BTEX w powietrzu atmosferycznym na obszarach miejskich
PublikacjaLotna związki organiczne, a wśród nich związki z grupy BTEX, odgrywają istotną rolę w chemii środowiska. Mogą one oddziaływać znacząco na abiotyczną jak i biotyczną część środowiska. Nie bez znaczenia jest również wpływ LZO na organizmy żywe w tym na zdrowie ludzkie. Ponadto posiadają one zdolność do kumulowania się w organizmach żywych zwiększając ryzyko zachorowań. Niektóre z nich mogą również niekorzystnie oddziaływać na organizmy...
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Passive sampling techniques in monitoring of BTEX in urban air = Technika dozymetrii pasywnej w monitoringu analitów z grupy BTEX w powietrzu atmosferycznym na obszarach miejskich
PublikacjaLotna związki organiczne, a wśród nich związki z grupy BTEX, odgrywają istotną rolę w chemii środowiska. Mogą one oddziaływać znacząco na abiotyczną jak i biotyczną część środowiska. Nie bez znaczenia jest również wpływ LZO na organizmy żywe w tym na zdrowie ludzkie. Ponadto posiadają one zdolność do kumulowania się w organizmach żywych zwiększając ryzyko zachorowań. Niektóre z nich mogą również niekorzystnie oddziaływać na organizmy...
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Transdermal transport of collagen and hyaluronic acid using water in oil microemulsion
PublikacjaCollagen and hyaluronic acid (HA) are biopolymers that affect the appearance and condition of the skin. Delivery of these compounds into the skin is highly challenging since have a number of disadvantageous properties, such as high molecular weight and hydrophilicity. Here, we evaluated the transdermal penetration of low and high molecular weight collagen and HA from microemulsions. A number of microemulsion formulations, differing...
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Karol Grębowski dr inż.
OsobyKarol Grębowski (dr inż.) pracuje jako adiunkt w Katedrze Technicznych Podstaw Projektowania Architektonicznego na Wydziale Architektury Politechniki Gdańskiej. Jego badania naukowe dotyczą zjawisk szybkozmiennych zachodzących podczas drgań konstrukcji budowlanych, obiektów mostowych (trzęsienia ziemi) oraz badania w zakresie metodologii projektowania budynków stanowiących system ochrony pasywnej (SOP) odpornych na uderzenia pojazdów...
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Ewa Hermanowicz prof. dr hab. inż.
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Performance tuning of chitosan-based membranes by protonated 2-Pyrrolidone-5-carboxylic acid-sulfolane DES for effective water/ethanol separation by pervaporation
PublikacjaToday, the applicability of deep eutectic solvents (DES) in various fields, including membrane science and technology, is extensively investigated. In pioneering works, we have implemented different DES as a component of chitosan (CS)-based flat membranes for pervaporation (PV) separation. Herein, we present a new protonated (by sulphuric acid) 2-Pyrrolidone-5-carboxylic acid: sulfolane DES, as a green additive for its chemical...
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Piotr Szczuko dr hab. inż.
OsobyDr hab. inż. Piotr Szczuko w 2002 roku ukończył studia na Wydziale Elektroniki, Telekomunikacji i Informatyki Politechniki Gdańskiej zdobywając tytuł magistra inżyniera. Tematem pracy dyplomowej było badanie zjawisk jednoczesnej percepcji obrazu cyfrowego i dźwięku dookólnego. W roku 2008 obronił rozprawę doktorską zatytułowaną "Zastosowanie reguł rozmytych w komputerowej animacji postaci", za którą otrzymał nagrodę Prezesa Rady...
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Separation of toluene from gas phase using supported imidazolium ionic liquid membrane
PublikacjaInvestigation on utilization of supported ionic liquids membranes for hydrocarbon separation from the gas phase was performed. Properties of membrane phase, wettability of supports, swelling effects and solubility of toluene were taken into account. Toluene permeation rates were significantly higher than those of pure nitrogen, the selectivity in a range of 17–341 was satisfying for separation. Despite the increase of viscosity...
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Urządzenie do wytwarzania gazowych mieszanin wzorcowych z wykorzystaniem procesu barbotażu oraz permeacji
PublikacjaReference gas mixtures are classified to reference materials and are mainly used for quality monitoring and identification of impurities in atmospheric air. They can be also used for calibration of measuring devices. Nowadays, there is a need to develop a new techniques for the preparation of reference gas mixtures [1, 2]. In this paper the design and the operating principles of instrument based on the use of barbotage and permeation...
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Comparison of the tests for equivalence of the measurement methods for measurement of PM10 dust in ambient air
PublikacjaThe paper presents the motives for conducting the equivalence tests and the reasons of discrepancies between the results of PM10 dust concentration obtained via the reference method and the methods based on 'on-site' measurement. The reference and non-reference methods of measurement of PM10 dust concentration in air have been discussed. Field tests for equivalence, following the Polish standard and the European Union (EU) guidelines,...
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UHF ESPAR antenna for simple Angle of Arrival estimation in UHF RFID applications
PublikacjaAn electronically switched beam antenna for localization of passive UHF RFID tags based on a simple Angle of Arrival (AoA) technique is proposed‥ Detailed antenna design and realization are presented together with corresponding simulations and measurement results. Experimental tests with passive UHF RFID tag show the validity of theoretical assumptions for application of the antenna in UHF RFID based localization systems.
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Topical delivery of pharmaceutical and cosmetic macromolecules using microemulsion systems
PublikacjaMicroemulsions are transparent, thermodynamically stable colloidal systems. Over the recent years, they have been increasingly investigated due to their potential as skin delivery vehicles for a wide range of drug molecules. The nanoscale particle size and the specificity of microemulsion components are the main features determining the skin permeation process. However, in order to effectively cross the skin barrier, the active...
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Monitorowanie i mapowanie zanieczyszczenia powietrza atmosferycznego przez związki z grupy BTEX (benzen, toluen, etylobenzen, ksylen) z wykorzystaniem techniki dozymetrii pasywnej do pobierania próbek analitów = Monitoring and mapping of atmospheric pollutans with the use of passive technique of sampling of BTEX (benzene, ethylbenzene, toluene, xylenes) analytes
PublikacjaWskutek działalności człowieka do atmosfery dostaje się coraz większa liczba substancji szkodliwych, uznanych za potencjalnie niebezpieczne dla organizmów żywych, głównie z uwagi na ich toksyczność. Do takich substancji zalicza się między innymi związki z grupy BTEX. Chcąc ocenić stopień narażenia populacji na obecność w powietrzu atmosferycznym analitów z grupy BTEX, niezbędne jest monitorowanie poziomu stężeń tych zanieczyszczeń...
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Influence of terpenes on indoor air quality
PublikacjaThe aim of this study was to investigate air quality in hairdresser salons, focusing on terpenes determination. Terpenes are known reactive volatile organic compounds that contribute to secondary organic aerosol formation. Those compounds are frequently found in cosmetic products as fragrance agents. Hairdresser salons are special kind of environment, where secondary organic aerosol concentration may be elevated. One hairdresser...
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New type T-Source inverter
PublikacjaThis paper presents different topologies of voltage inverters with alternative input LC networks. The basic topology is known in the literature as a Z-source inverter (ZSI). Alternative passive networks were named by the authors as T-sources. T-source inverter has fewer reactive components in comparison to conventional Z-source inverter. The most significant advantage of the T-source inverter (TSI) is its use of a common voltage...
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Złote monety bulionowe – testowanie pasywnego charakteru inwestycji
PublikacjaCel – Wyznaczenie składu optymalnego portfela inwestycyjnego o minimalnym ryzyku, zawierającego inwestycję w polskie monety bulionowe (Orzeł Bielik) oraz inwestycję na polskiej giełdzie papierów wartościowych. Testowanie pasywnego charakteru inwestycji w monety. Metodologia badania – Konstrukcja portfeli inwestycyjnych o minimalnym ryzyku według teorii H.M. Markowitza. Autorska metoda badania pasywnego charakteru inwestycji...
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Effect of native air-formed oxidation on the corrosion behavior of AA7075 aluminum alloys
PublikacjaThe microstructure of aluminum alloys plays a key role in their corrosion resistance. In particular, the presence of intermetallic precipitates differing in the potential from the alloy matrix induces local corrosion. The study presents the effect of native air-formed oxidation on the corrosion behavior of AA 7075 aluminum alloy. Various microscopic and spectroscopic techniques were used to examine the changes occurring in the...
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Green Sample Collection
PublikacjaThe term of “green sample collection” is directly associated with both passive and dynamic analytical tools which allow for simultaneous management of the stage of collection and isolation and/or enrichment of a broad spectrum of chemical compounds from environmental samples. The use of passive sampling techniques at the stage of sample collection makes it possible to obtain in a simple yet inexpensive manner an analytical information...
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Electrical mapping of AISI 304 stainless steel subjected to intergranular corrosion performed by means of AFM-LIS in the contact mode
PublikacjaThe paper presents results of the AFM-based approach to local impedance spectroscopy (LIS) measurements performed in a 20 20 lm grid within an austenite grain–grain boundary region for sensitized AISI 304 stainless steel (SS). Maps of electrical parameters obtained on the basis of localized impedance spectra were demonstrated, presenting their changes and correlation with the sample topography. Performed research revealed significant...
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Near Field Coupled Wireless Microwave Sensor
PublikacjaThis paper presents a wireless planar microwave sensor operating at industrial scientific and medical (ISM) frequency for the detection of dielectric materials. The microwave sensor consists of a reader (ground defected microstrip coupled line) and a passive tag where a complementary split-ring resonator (CSRR) is made on the commercially available copper-foil. The CSRR is a peel-off type tag that is excited using the near field...
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CM Voltage Compensators for Power Electronic Interfaces
PublikacjaThe experimental results presented in the paper have shown that the application of the PEIs might cause EMC related problems, especially in the case of the application of a group of connected converters. The most convenient way to reduce EMI currents and prevent aggregation of EMI currents introduced by a group of converters is through passive compensation of voltage interference sources inside of the single converters. In the...
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Signal conditioning for examination of shallow-water acoustic noise correlation properties
PublikacjaThe article describes the process of signal conditioning for examination of acoustic noise correlation properties in shallow water. Knowledge of these properties is very important for the design processes of passive and active hydroacoustic systems. This paper focuses on the above issue from the point of view of passive sonar. In sonar systems, signal processing algorithms operate on both useful acoustic signals, and accompanying...
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Analysis of activity of people using motion sensors
PublikacjaThe article presents the designed and implemented system for activity monitoring of people using passive motion sensors and methods for activity maps generation. In the paper he method is presented and results obtained for simulated data and for data from observations with the participation of people.
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Prediction of ringing frequencies in DC-DC boost converter
PublikacjaIn the paper ringing phenomena in a DC-DC boost converter is presented. The ringing frequency is calculated using an analytical formula. The necessary wide band models of MOSFET transistor, passive and parasitics are described. The calculation results are verified in simulation and laboratory tests.
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Hydrogen effects in duplex stainless steel welded joints - electrochemical studies
PublikacjaIn this work results on the influence of hydrogen on passivity and corrosion resistance of 2205 duplex stainless steel (DSS) welded joints are described. The results were discussed by taking into account three different areas on the welded joint: weld metal (WM), heat-affected zone (HAZ) and parent metal. The corrosion resistance was qualified with the polarization curves registered in a synthetic sea water. The conclusion is that,...
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Plate heat exchanger with porous structure for potential use in ORC system
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The passive intensification was obtained by a modification of the heat transfer surface, which was covered by a metallic porous microlayer. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one...
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Plate heat exchanger with porous structure for potential use in ORC system
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The passive intensification was obtained by a modification of the heat transfer surface, which was covered by a metallic porous microlayer. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one...
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Unconventional and user-friendly sampling techniques of semi-volatile organic compounds present in an indoor environment: An approach to human exposure assessment
PublikacjaThe commonly applied solutions used to assess the potential risk of human exposure to semi-volatile organic compounds (SVOCs) are based on the investigation of biological samples collected in an invasive or non-invasive manner. For SVOCs, which are typically introduced to humans through the respiratory system, dermal adsorption, or digestive system, sampling solutions generally used in the indoor environments are classified as...
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Control strategy for the multilevel cascaded H-bridge converter
PublikacjaThe paper presents the control strategy for Cascaded H-bridge (CHB) converter . The converter output voltage using Space-Vector Pulse Width Modulation (SV-PWM) strategy is controlled. The DC-link voltages are controlled by appropriate choice of H-Bridges and appropriate choice of active and passive vectors.
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Urban Prototyping in CAVE Cooperation Between the Academy of Fine Arts in Gdansk and the Gdansk University of Technology
PublikacjaThe paper describes results of cooperation between the Passive Architecture Laboratory at the Academy of Fine Arts in Gdańsk and the Immersive 3D Visualization Lab at the Gdańsk University of Technology. The authors as the design supervisors (respectively for a team of architects and a team of IT specialists) present advantages and disadvantages of urban design with use of virtual reality.
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Neurochemical changes underlying cognitive impairment in olfactory bulbectomized rats and the impact of the mGlu5-positive allosteric modulator CDPPB
PublikacjaThe olfactory bulbectomized (OBX) rat model is a well-established model of depression in which antidepressant drugs reverse deficits in the passive avoidance test 14 days after administration. Recently, the olfactory bulbectomized rat model has been proposed to be a model of Alzheimer’s disease (AD), and the available data indicate similarities between the changes that typically occur in AD and those observed in OBX animals. In...
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Determination of pharmaceuticals in fish: method optimization and occurrence in different species from Mediterranean rivers
PublikacjaThe multi-residue analytical method developed, based on accelerated solvent extraction, gel permeation chromatography purification and UPLC-MS/MS analysis allowed the simultaneous determination of 21 pharmaceuticals. Recoveries obtained for most of the target compounds were higher than 50%. The application of UPLC-MS/MS operating in the MRM mode, with two transitions monitored for each compound, provided good sensitivity and selectivity....
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Quality measure of VoIP services in carrier grade systems
PublikacjaThis paper describes passive measurement method of VoIP services quality in carrier grade systems, engaging slight system resources. Measurement is based on analyzing quality information in sender and receiver reports in RTCP packets sent by the end points of RTP session. Data is analyzed and stored by Session Boarder Controllers SBC. Objective evaluation of VoIP calls is based on quality information of IP connection and voice...
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Comparison of Impedance-Source Networks for Two and Multilevel Buck–Boost Inverter Applications
Publikacjampedance-source networks are an increasingly popular solution in power converter applications, especially in single-stage buck-boost power conversion to avoid additional front-end dc-dc power converters. In the survey papers published, no analytical comparisons of different topologies have been described, which makes it difficult to choose the best option. Thus, the aim of this paper is to present a comprehensive analytical comparison...
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Effect of cobalt addition on the corrosion behaviorof near equiatomic NiTi shape memory alloy in normal saline solution: electrochemical and XPS studies
PublikacjaThe electrochemical and corrosion (uniform and localized) behavior of a binary Ni52Ti48 shape memory alloy (SMA) and two ternary Ni52Ti48-xCox (x = 1.5 and 4.0 wt.%) SMAs were studied. Measurements were conducted in 0.9% NaCl solution at 37 oC employing various electrochemical methods. These include: linear polarization resistance (LPR), linear sweep voltammetry (LSV), chronoamperometry and dynamic electrochemical impedance spectroscopy...
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Novel single-stage buck-boost inverter with unfolding circuit
PublikacjaA novel solution of a single-stage buck-boost inverter with unfolding circuit at the output stage is presented. The inverter has a wide range of input voltage regulation, minimum passive components and a very flexible control structure. It can be applied for renewable energy systems where high power density is required. Our simulation results confirmed all theoretical statements
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Discrete Modelling of Micro-structural Phenomena in Granular Shear Zones
PublikacjaThe micro-structure evolution in shear zones in cohesionless sand for quasi-static problems was analyzed with a discrete element method (DEM). The passive sand failure for a very rought retaining wall undergoing horizontal translation towards the sand backfill was discussed. To simulate the behaviour of sand, the spherical discrete element model was used with elements in the form of rigid spheres with contacts moments.
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Effectiveness of toluene separation from gas phase using supported ammonium ionic liquid membrane
PublikacjaAmmonium ionic liquids (ILs) are relatively cheap in synthesis and environmentally benign and despite that they have been very rarely used in gas separation. In this research we used several ammonium ILs as liquid membranes for removal of residual toluene from gas phase. Ionic liquids used in this study were composed of bis(trifluoromethylsulfonyl)imide anion [Tf2N] and trimethylbutylammonium [N1114], trietylbutylammonium [N2224],...
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Current trends in the field of steganalysis and guidelines for constructions of new steganalysis schemes
PublikacjaThe paper concerns blind steganalysis techniques in the passive steganalysis scenario designed to detect the steganographic cover modification schemes. The goal is to investigate the state-of-art in the field of steganalysis, and, above all, to recognize current trends existing in this field and determine guidelines for constructions of new steganalysis schemes. The intended effects are to examine the possibilities for the development...
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Determination of Earth Pressure and Displacement of the Retaining Structure According to the Eurocode 7-1
PublikacjaComparative analysis of standard guidelines and findings given in EC7-1 and in Polish Standard PN-83/B-03010. Discussed guidelines concerning active and passive earth pressure as well as at rest pressure state. Wall displacement causing limit states of earth pressure and resistance. Interactive assumptions concerning intermediate earth pressure and resistance values. Conclusions and final remarks.
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Badania eksperymentalne strefy przypodporowej żelbetowych belek częściowo sprężonych
PublikacjaThis project refers to the study the shear zone, under full and partial prestressing in comparison to beams with passive reinforcement.For comparison, variable parameters have been determined:- a/d (from 1,5 to 3,5) - it's shear span to effective depth of the beam . Assuming constant geometrical quantities, "a" is variable.- 26 beams had no vertical shear reinforcement, and the other 26 had closed stirrups.- prestressing intensity...