Wyniki wyszukiwania dla: EXPERIMENTAL METHODS
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Expert assessment of arguments: a method and its experimental evaluation
PublikacjaArgument structures are commonly used to develop and present cases for safety, security and other properties. Such argument structures tend to grow excessively. To deal with this problem, appropriate methods of their assessment are required. Two objectives are of particular interest: (1) systematic and explicit assessment of the compelling power of an argument, and (2) communication of the result of such an assessment to relevant...
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New concept and analysis of the multicell piezoelectric motor
PublikacjaThis work presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a ”single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
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Impedance Studies of Phosphate-iron Glasses Containing Niobium and Titanium
PublikacjaThe ac and dc conductivity in phosphate-iron-niobate glasses with addition of titanium oxide was investigated as a function of temperature and frequency with the use of impedance spectroscopy. The topography and microstructure of glasses were investigated by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and confocal microscopy methods. The obtained results show that all samples are amorphous but they...
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Chosen Analysis Results Of The Prototype Multicell Piezoelectric Motor
PublikacjaThis paper presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a “single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
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Rapid design optimization of antennas using variable-fidelity EM models and adjoint sensitivities
PublikacjaPurpose – Development of techniques for expedited design optimization of complex and numerically expensive electromagnetic (EM) simulation models of antenna structures validated both numerically and experimentally. The paper aims to discuss these issues. Design/methodology/approach – The optimization task is performed using a technique that combines gradient search with adjoint sensitivities, trust region framework, as well as...
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Chemical, thermal and laser processes in recycling of photovoltaic silicon solar cells and modules
PublikacjaIn recent years, photovoltaic power generation systems have been gaining unprecedented attention as an environmentally beneficial method to solve the energy problem. From the economic point of view the pure silicon, which can be recapture from the used cells, is the most important material due to its cost and shortage. In the paper selected methods of used or damaged module and cells recycling and experimental results are presented....
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Stiffness assessment of the laminate recovered from end-of-life wind turbine blade
PublikacjaIn the paper the stiffness parameters of the laminate recovered from an aerodynamic shell of a decommissioned wind turbine blade are evaluated. The aim of the work is to assess selected methods for identifying material data, as well as to estimate the level of stiffness degradation during turbine operation. Several practical identification methods are presented and compared. Two concepts of a single laminate layer are considered,...
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A comparative study of English viseme recognition methods and algorithms
PublikacjaAn elementary visual unit – the viseme is concerned in the paper in the context of preparing the feature vector as a main visual input component of Audio-Visual Speech Recognition systems. The aim of the presented research is a review of various approaches to the problem, the implementation of algorithms proposed in the literature and a comparative research on their effectiveness. In the course of the study an optimal feature vector construction...
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A comparative study of English viseme recognition methods and algorithm
PublikacjaAn elementary visual unit – the viseme is concerned in the paper in the context of preparing the feature vector as a main visual input component of Audio-Visual Speech Recognition systems. The aim of the presented research is a review of various approaches to the problem, the implementation of algorithms proposed in the literature and a comparative research on their effectiveness. In the course of the study an optimal feature vector...
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Solubility of dapsone in deep eutectic solvents: Experimental analysis, molecular insights and machine learning predictions
PublikacjaBackground. Dapsone (DAP) is an anti-inflammatory and antimicrobial active pharmaceutical ingredient used to treat, e.g., AIDS-related diseases. However, low solubility is a feature hampering its efficient use. Objectives. First, deep eutectic solvents...
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Doubly miniaturized rat-race hybrid coupler
PublikacjaTwo complementary miniaturization techniques have beenapplied to reduce the size of a rat-race hybrid coupler: (i) conventional microstrip sections have been replaced with their diminished lowimpedance counterparts as the first step of size reduction and (ii) novel fractal-shaped compact microstrip resonant cells dedicated to efficiently shorten low-impedance transmission line segments have been implemented as the second step of...
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Induction machine behavioral modeling for prediction of EMI propagation.
PublikacjaThis paper presents the results of wideband behavioral modeling of an induction machine (IM). The proposed solution enables modeling the IM differential- and common-mode impedance for a frequency range from 1 kHz to 10 MHz. Methods of parameter extraction are derived from the measured IM impedances. The developed models of 1.5 kW and 7.5 kW induction machines are designed using the Saber Sketch scheme editor and simulated in the...
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Porous Phantoms Mimicking Tissues – Investigation of Optical Parameter Stability Over Time
PublikacjaIn terms of optical parameters, optical phantoms can now replace live tissues and be used to validate optical measurement methods. Therefore, whether these parameters would be maintained after storage for 6 months was examined. The absorption and scattering coefficients were obtained from the measured transmittance and reflectance measurements taken 6 months apart and then compared. All of the measurements were conducted using...
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Prediction of metal deformation due to line heating; an alternative method of mechanical bending, based on artificial neural network approach
PublikacjaLine heating is one of the alternative methods of forming metals and this kind of forming uses the heating torch as a source of heat input. During the process, many parameters are considered like the size of the substrate, thickness, cooling method, source power intensity, the travel speed of the power source, the sequence of heating, and so on. It is important to analyze the factors affecting the...
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A Data Driven Model for Predicting RNA-Protein Interactions based on Gradient Boosting Machine
PublikacjaRNA protein interactions (RPI) play a pivotal role in the regulation of various biological processes. Experimental validation of RPI has been time-consuming, paving the way for computational prediction methods. The major limiting factor of these methods has been the accuracy and confidence of the predictions, and our in-house experiments show that they fail to accurately predict RPI involving short RNA sequences such as TERRA RNA....
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Theoretical Assessment of Excited State Gradients and Resonance Raman Intensities for the Azobenzene Molecule
PublikacjaThe ground state geometries and vibrational frequencies as well as the excitation energies and excited state gradients of the S 1(nπ*) and S 2(ππ * ) states of trans - and cis -azobenzene are investigated by several DFT methods, namely B3LYP, PBE, M06-2X, CAM-B3LYP, and ω B97X. Excited state properties and in particular gradients are also assessed using the wave function based methods EOM-CCSD and RASPT2/RASSCF. Comparison with...
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Negative CO2 Emission Gas Power Plant As Technology for Utilization of Sewage Sludge, Production of Electrical Energy, and CO2 Capture - Case of Chamber Under Transpiration Cooling
PublikacjaThis work focuses on the concept developed in the nCO2PP project, which aims to demonstrate a technology that allows to achieve negative CO2 emissions through Carbon Capture and Storage (CCS) applied to sewage sludge. A feedstock is first gasified, then the resulting syngas is burned in a semi-closed oxy-fuel gas turbine with pure oxygen and water, using the advantages of oxy-combustion, to ease the capture of CO2 in the resulting...
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Robust and Efficient Machine Learning Algorithms for Visual Recognition
PublikacjaIn visual recognition, the task is to identify and localize all objects of interest in the input image. With the ubiquitous presence of visual data in modern days, the role of object recognition algorithms is becoming more significant than ever and ranges from autonomous driving to computer-aided diagnosis in medicine. Current models for visual recognition are dominated by models based on Convolutional Neural Networks (CNNs), which...
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A new construction of shell-and-tube heat exchanger with impinging jets and minichannels technologies for heat recovery from gases – experimental analysis
PublikacjaA dynamic development of technologies allowing waste heat utilization is observed in a correspondence with a pro-ecological approach of the zero waste idea. Such approach becomes the most demanding in the area of low-temperature was heat sources, especially gaseous media. Till now, they were usually not utilized due to unfavorable thermal conditions and high costs. Therefore, the zero waste approach directs research on techniques...
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Modeling of Passive and Forced Convection Heat Transfer in Channels with Rib Turbulators
PublikacjaThe main goal of the research presented in this paper was the experimental and numerical analysis of heat enhancement and aerodynamic phenomena during air flow in a channel equipped with flow turbulators in the form of properly configured ribs. The use of ribs intensifies the heat transfer and at the same time increases not only the flow resistance but also the energy costs. Therefore, designing modern heat exchangers with optimal...
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New trends in development of micro heat exchangers for ORC's
PublikacjaIn the paper, new trends in development of micro heat exchangers for CHP are presented. Main attention is concentrated on the question, how channels size and thermal development lenght affect the heat transfer. New types of micro heat exchangers developed at the Institute of Fluid-Flow Machinery PAS and the methoda of their design are presented. The new experimental testing methods of the micro-channel heat exchangers, new algorithms...
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Short-range order structure and free volume distribution in liquid bismuth: X-ray diffraction and computer simulations studies
PublikacjaThe structure of liquid bismuth was studied by X-ray diffraction and computer simulation methods. The contraction of the atomic structure within the first coordination sphere in the temperature interval of 575- 1225 K is reported. The temperature dependencies of the coordination numbers and of the free volume are analysed. On the basis of the temperature dependencies of the free volume, the temperature dependencies of viscosity...
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MP3vec: A Reusable Machine-Constructed Feature Representation for Protein Sequences
Publikacja—Machine Learning (ML) methods have been used with varying degrees of success on protein prediction tasks, with two inherent limitations. First, prediction performance often depends upon the features extracted from the proteins. Second, experimental data may be insufficient to construct reliable ML models. Here we introduce MP3vec, a transferable representation for protein sequences that is designed to be used specifically for sequence-to-sequence...
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Numerical Modelling of Structures with Uncertainties
PublikacjaThe nature of environmental interactions, as well as large dimensions and complex structure of marine offshore objects, make designing, building and operation of these objects a great challenge. This is the reason why a vast majority of investment cases of this type include structural analysis, performed using scaled laboratory models and complemented by extended computer simulations. The present paper focuses on FEM modelling...
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The conception of energetic investigations of the multisymptom fatigue of the simple mechanical systems' constructional materials
PublikacjaThe article presents the basic assumptions of the research project aimed, as the main scientific purpose, an identification of the slow-changeable energy processes surrounding the high-cycle fatigue of constructional materials within the plain mechanical system, especially the marine one, for diagnostic purposes. There is foreseen an application of alternative diagnostic methods based on energetic observations of the multi-symptom,...
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Anharmonic Infrared Spectroscopy through the Fourier Transform of Time Correlation Function Formalism in ONETEP
PublikacjaDensity functional theory molecular dynamics (DFT-MD) provides an efficient framework for accurately computing several types of spectra. The major benefit of DFTMD approaches lies in the ability to naturally take into account the effects of temperature and anharmonicity, without having to introduce any ad hoc or a posteriori corrections. Consequently, computational spectroscopy based on DFT-MD approaches plays a pivotal role in...
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INVESTIGATION OF THE LOMBARD EFFECT BASED ON A MACHINE LEARNING APPROACH
PublikacjaThe Lombard effect is an involuntary increase in the speaker’s pitch, intensity, and duration in the presence of noise. It makes it possible to communicate in noisy environments more effectively. This study aims to investigate an efficient method for detecting the Lombard effect in uttered speech. The influence of interfering noise, room type, and the gender of the person on the detection process is examined. First, acoustic parameters...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF HYDRAULIC COMPONENTS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
PublikacjaDesigners of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental...
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Numerical Analysis of Mice Carotid Arteries’ Response Emphasizing the Importance of Material Law Constants’ Validation
PublikacjaIn this paper, a detailed validation of the passive material properties of mice carotid arteries and constants of the Fung and Holzapfel hyperelastic material laws is conducted by means of static nonlinear FEM analyses. The response of the carotid arteries in an inflation test is studied here for the following mouse models: wild-type, mdx, sgcd−/−, Eln+/+, Eln+/−, Fbln5+/+, and Fbln5−/−. All FEM computations are conducted on models...
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Hydrogen production from ethanol In nitrogen microwave plasma At atmospheric pressure
PublikacjaHydrogen seems to be one of the most promising alternative energy sources. It is a renewable fuel as it could be produced from e.g. waste or bio-ethanol. Furthermore hydrogen is compatible with fuel cells and is environmentally clean. In contrast to conventional methods of hydrogen production such as water electrolysis or coal gasification we propose a method based on atmospheric pressure microwave plasma. In this paper we present...
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Automatic Correction of Non-Anechoic Antenna Measurements Using Complex Morlet Wavelets
PublikacjaReal-world performance of antennas is normally tested in anechoic chambers (ACs). Alternatively, experimental validation can be performed in non-anechoic environments and refined in the course of post-processing. Unfortunately, the existing methods are difficult to setup and prone to failure. In this letter, a wavelet-based framework for correction of non-anechoic antenna measurements has been proposed. The method involves automatic...
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Dual-wavelength polarimeter application in investigations of the optical activity of a langasite crystal
PublikacjaA method of high accuracy polarimetry, which includes optical activity measurements systematic errors, was realized with dual-wavelength polarimeter for two wavelengths of 635 and 650 nm. Simultaneous measurements with neighboring wavelengths significantly improved the data processing, by increasing the amount of data to eliminate the systematic errors. For langasite crystal La3Ga5SiO14 we measured temperature dependence of the...
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THE EFFECT OF WOOD DRYING METHOD ON THE GRANULARITY OF SAWDUST OBTAINED DURING THE SAWING PROCESS USING THE FRAME SAWING MACHINE
PublikacjaThe experimental results of the study focused on the effect of drying processes of warm air drying at the temperature of 6580°C and warm air-steam mixture drying at the temperature of 105°C of pine and beech wood to the size of sawdust grains created by cutting using RPW 15M frame saw is presented in the paper. Particle size analysis of dry sawdust was performed using two methods - screening method and optical method based on...
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Visual Data Encryption for Privacy Enhancement in Surveillance Systems
PublikacjaIn this paper a methodology for employing reversible visual encryption of data is proposed. The developed algorithms are focused on privacy enhancement in distributed surveillance architectures. First, motivation of the study performed and a short review of preexisting methods of privacy enhancement are presented. The algorithmic background, system architecture along with a solution for anonymization of sensitive regions of interest...
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Machine-learning methods for estimating compressive strength of high-performance alkali-activated concrete
PublikacjaHigh-performance alkali-activated concrete (HP-AAC) is acknowledged as a cementless and environmentally friendly material. It has recently received a substantial amount of interest not only due to the potential it has for being used instead of ordinary concrete but also owing to the concerns associated with climate change, sustainability, reduction of CO2 emissions, and energy consumption. The characteristics and amounts of the...
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Experimental Designs of Mass Customized Passive Single-family Houses - Prospects and Limitations
PublikacjaAbstract The article deals with case studies of selected architectural designs of the past fifteen years the authors of which intended to rethink both the typology and the means of constructing single family houses. The analysis covers contemporary design issues such as variation, curvilinearity, customization, digital manufacturing and ecological concerns. The purpose behind the research was to establish in what way new design...
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Data-Driven Modeling of Mechanical Properties of Fiber-Reinforced Concrete: A Critical Review
PublikacjaFiber-reinforced concrete (FRC) is extensively used in diverse structural engineering applications, and its mechanical properties are crucial for designing and evaluating its performance. The compressive, flexural, splitting tensile, and shear strengths of FRCs are among the most important attributes, which have been discussed more extensively than other properties. The accurate prediction of these properties, which are required...
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Simulation-driven design of compact ultra-wideband antenna structures
PublikacjaPurpose–The purpose of this paper is to investigate strategies and algorithms for expedited designoptimization and explicit size reduction of compact ultra-wideband (UWB) antennas.Design/methodology/approach–Formulation of the compact antenna design problem aiming atexplicit size reduction while maintaining acceptable electrical performance is presented. Algorithmicframeworks are described suitable for handling various design situations...
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Digital structures for high-speed signal processing
PublikacjaThe work covers several issues of realization of digital structures for pipelined processing of real and complex signals with the use of binary arithmetic and residue arithmetic. Basic rules of performing operations in residue arithmetic are presented along with selected residue number systems for processing of complex signals and computation of convolution. Subsequently, methods of conversion of numbers from weighted systems to...
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Improving the Accuracy in Sentiment Classification in the Light of Modelling the Latent Semantic Relations
PublikacjaThe research presents the methodology of improving the accuracy in sentiment classification in the light of modelling the latent semantic relations (LSR). The objective of this methodology is to find ways of eliminating the limitations of the discriminant and probabilistic methods for LSR revealing and customizing the sentiment classification process (SCP) to the more accurate recognition of text tonality. This objective was achieved...
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COMPARISON OF PREDICTIVE METHODS FOR FLOW BOILING HEAT TRANSFER IN CONVENTIONAL CHANNELS AND MINICHANNELS – THE EFFECT OF REDUCED PRESSURE
PublikacjaIn the paper are presented the results of follow on studies from [1]–[3] using authors own model to predict heat transfer coefficient during flow boiling. The model has been tested against a large selection of experimental data collected from various researchers to investigate the sensitivity of the in-house developed model. The collected experimental data came from various studies from literature and were conducted for the full...
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Characterization of the Functionally Graded Shear Modulus of a Half-Space
PublikacjaIn this article, a method is proposed for determining parameters of the exponentialy varying shear modulus of a functionally graded half-space. The method is based on the analytical solution of the problem of pure shear of an elastic functionally graded half-space by a strip punch. The half-space has the depth-wise exponential variation of its shear modulus, whose parameters are to be determined. The problem is reduced to an integral...
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On some problems in determining tensile parameters of concrete model from size effect tests
PublikacjaThe paper presents results of numerical simulations of size effect phenomenon in concrete specimens. The behaviour of in-plane geometrically similar notched and unnotched beams under three-point bending is investigated. In total 18 beams are analysed. Concrete beams of four different sizes and five different notch to depth ratios are simulated. Two methods are applied to describe cracks. First, an elasto-plastic constitutive law...
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Piezo 2011, Electroceramics for End-Users VI
PublikacjaThis work extends a power harvesting with using piezoelectric materials. Experimental presents the development of a piezoelectric MEMS generator which has the ability to scavenge mechanical energy of ambient vibrations from their surroundings and transform it into electrical energy that can be used in energy storage applications. Recent literature shows that piezoelectric transduction has received the most attention for vibration-to-electricity...
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Wearable system supporting navigation of the blind
PublikacjaImproving blind people comfort of life is a problem ofgreat importance. Fortunately, new technolgies provide us withadditional methods to improve everyday life of the blind and visuallyimpaired. The paper presents experimental system made byresearchers from Department of Geoinformatics of Gdansk Universityof Technology, which is capable of finding the route from theindicated source to chosen destination, using dedicated digital...
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Excitation of Circularly Polarized Wave via Single-Feed Metasurface-Integrated Compact Antenna for Internet of Things
PublikacjaA compact circularly polarized (CP) quasi-omnidirectional antenna is introduced for internet of things (IoT). The structure consists of two components implemented on FR-4 substrates, and sep-arated by an air gap: one printed with a rectangular patch fed through a matching network, and another with a metasurface and a ground plane. Two different methods for impedance matching are employed. An equivalent circuit model of the antenna...
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Influence of drying mode and feed per tooth rate on the fine dust creation in pine and beech sawing on a mini sash gang saw
PublikacjaThe experimental results of the study focused on the effect of drying processes of modified air drying and warm air steam mixture drying of pine and beech wood on the size of sawdust particles created in cutting using PRW-15M sash gang saw, are presented in the paper. Particle size analysis of dry sawdust was performed using two methods—sieving method and laser diffraction analysis. The results showed that the drying process did...
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Electron attachment to hexafluoropropylene oxide (HFPO)
PublikacjaWe probe the electron attachment in hexafluoropropylene oxide (HFPO), C3F6O, a gas widely used in plasma technologies. We determine the absolute electron attachment cross section using two completely different experimental approaches: (i) a crossed-beam experiment at single collision conditions (local pressures of 5 × 10−4 mbar) and (ii) a pulsed Townsend experiment at pressures of 20–100 mbar. In the latter method, the cross sections...
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Analysis of EN 1993-1-6 guidelines about determining amplitudes of equivalent imperfections of steel cylindrical shells subjected to uniform external pressure
PublikacjaCivil engineering structures should be designed with reference to relevant standards. One of them is a Eurocode 3 standard EN 1993-1-6:2007: Design of steel structures Part 1-6: Strength and Stability of Shell Structures. According to this standard, the value of buckling load can be determined using different approaches: classical hand calculations (stress design) and geometrical and material non-linear analysis of an imperfect...
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International Conference on Experimental Implementation of Quantum Computation
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