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Search results for: EFFECTIVE WIDTH OF FLANGE
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Crack Detection in Metallic Surfaces Based on Dumbbell-Shaped Defected Ground Structures in Microstrip Technology
PublicationIn this paper, a novel crack detection sensor using a microstrip loaded with a Dumbbell-Shaped Defected Ground Structure (DS-DGS) is proposed. The sensing element is etched in the ground plane of a microstrip line and it is easy to fabricate. The electromagnetic (EM) field of the microstrip couples to the DS-DGS, thus demonstrating a bandstop behavior. It is shown that in the presence of a crack in a metallic surface underneath the...
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Regularized Local Basis Function Approach to Identification of Nonstationary Processes
PublicationThe problem of identification of nonstationary stochastic processes (systems or signals) is considered and a new class of identification algorithms, combining the basis functions approach with local estimation technique, is described. Unlike the classical basis function estimation schemes, the proposed regularized local basis function estimators are not used to obtain interval approximations of the parameter trajectory, but provide...
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Better polynomial algorithms for scheduling unit-length jobs with bipartite incompatibility graphs on uniform machines
PublicationThe goal of this paper is to explore and to provide tools for the investigation of the problems of unit-length scheduling of incompatible jobs on uniform machines. We present two new algorithms that are a significant improvement over the known algorithms. The first one is Algorithm 2 which is 2-approximate for the problem Qm|p j = 1, G = bisubquartic|Cmax . The second one is Algorithm 3 which is 4-approximate for the problem Qm|p...
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IV Pomorska Uczniowska Konferencja Naukowa "Zdolni z Pomorza" 21.11.2020
e-Learning Courses -
Marcin Wekwejt dr inż.
PeopleMarcin Wekwejt, absolwent studiów inżynierskich w inż. biomedycznej (2016; Politechnika Bydgoska im. J. i J. Śniadeckich & Collegium Medicum im. L. Rydygiera), studiów magisterskich w inż. mechaniczno-medycznej (2018; Politechnika Gdańska & Gdański Uniwersytet Medyczny) oraz studiów doktoranckich w dyscyplinie inż. materiałowej (2021, Politechnika Gdańska). Uzyskał z wyróżnieniem stopień naukowy doktora nauk inżynieryjno-technicznych...
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Decisional DNA based intelligent knowledge model for flexible manufacturing system
PublicationModeling an effective mechanism for design and control strategies for the implementation of a flexible manufacturing system (FMS) has been a challenge. Consequently, to overcome this issue various techniques have applied in the past but most of these models are effective only for some specific situation or an element of FMS. In this study, the knowledge representation technique of Decisional DNA (DDNA) is applied to FMS to develop...
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Microstrip four-port circulator using a ferrite coupled line section
PublicationThis paper describes an alternative configuration of a four-port circulator realized in a microstrip ferrite coupled line technology. The proposed fully planar device employs two three-port circulators consisting of a ferrite coupled line junction and T junction. Both circulators are connected through the same arm, hence, the problem of anti-parallel magnetization met in this type of circulators is avoided without the increase...
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The differential impact of a density of Polish pine wood on cutting forces with its origin region taken into consideration
PublicationIn the article the dependence of cutting forces in a function the density of wood with regard to the wood origin are presented. Samples used in experiment were with Scotch pine (Pinus sylvestris L.) originating from four provenances in Poland (Figure 1). Wood density was measured by two methods: stereometric method (global density) and radiometric method (local density). Stereometric method consists in measurements the volume...
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Interactions using passive optical proximity detector
PublicationIn this paper we evaluated the possible application of a passive, optical sensor as an interface for human-smart glasses interactions. The designed proximity sensor is composed of set of photodiodes and the appropriate hardware and software components. First, experiments were performed for the estimations of such parameters as distance to an object, its width and velocity. Achieved results were satisfactory. Therefore, next, a...
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An Objective Focussing Measure for Acoustically Obtained Image
PublicationIn scientific literature many parameters of an image sharpness can be defined, that can be used for the evaluation of display energy concentration (EC). This paper proposes a new, simple approach to EC quantitative evaluation in spectrograms, which are used for the analysis and visualization of sonar signals. The presented approach of the global-image EC measure was developed to the evaluation of EC in arbitrary direction (or at...
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Hybrid Modulation for Modular Voltage Source Inverters with Coupled Reactors
PublicationThis paper proposes and discusses a concept of a hybrid modulation for the control of modular voltage source inverters with coupled reactors. The use of coupled reactors as the integrating elements leads to significant reduction in the size and weight of the circuit. The proposed modulation combines novel coarsely quantized pulse amplitude modulation (CQ-PAM) and innovative space-vector pulse width modulation (SVPWM). The former...
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Stress analysis of a strip under tension with a circular hole
PublicationThe paper addresses stress analysis of a strip with a circular hole under uniform uniaxial tension based oncircumferential stress expressionρπ. Stresses are analyzed in the infinite-length strips under tension with holes, the ratioof the hole radiusa to the strip half-widthb is either equal to:κ =a/b = 0.1 orκ = 0.5. Circumferential stresses aredetermined in selected cross-sections of the strip. The stress diagrams display local...
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Formowanie wektorów napięcia wyjściowego w pięciofazowych falownikach napięcia
PublicationW falownikach pięciofazowych, załączenie wektorów aktywnych powoduje jednoczesne formowane dwóch, zależnych od siebie wektorów napięcia wyjściowego. Sterowanie pięciofazowymi silnikami indukcyjnymi wymaga, aby wektory te miały ściśle określone długości i położenia. Niezależne formowanie dwóch wektorów napięcia o parametrach określonych w układzie sterowania silnikiem wymaga zastosowania odpowiedniej strategii Modulacji Szerokości...
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Study of Different Advanced Oxidation Processes for Wastewater Treatment from Petroleum Bitumen Production at Basic pH
PublicationEffluents from production of petroleum bitumens were submitted to treatment by three different AOPs at basic pH (i.e., O3, H2O2 and the combination of O3 and H2O2, a so-called peroxone). The paper presents studies on the identification and monitoring of the volatile organic compounds (VOCs) degradation present in the effluents and formation of byproducts, COD, BOD5, sulfide ions, biotoxicity, and biodegradability changes during...
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Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublicationChemical vapor transport (CVT) method is widely used for bulk black phosphorus (BP) fabrication. In this work, we demonstrate that CVT provides a route for the fabrication of BP nanoribbons and nanobelts. This method consists of a two-step procedure, including initial BP column growth using the CVT technique, followed by ultrasonic treatment and centrifugation. The obtained nanostructures preserve BP column dimensions, forming...
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The complexity of bicriteria tree-depth
PublicationThe tree-depth problem can be seen as finding an elimination tree of minimum height for a given input graph G. We introduce a bicriteria generalization in which additionally the width of the elimination tree needs to be bounded by some input integer b. We are interested in the case when G is the line graph of a tree, proving that the problem is NP-hard and obtaining a polynomial-time additive 2b-approximation algorithm. This particular...
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Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublicationChemical vapor transport (CVT) method is widely used for bulk black phosphorus (BP) fabrication. In this work, we demonstrate that CVT provides a route for the fabrication of BP nanoribbons and nanobelts. This method consists of a two-step procedure, including initial BP column growth using the CVT technique, followed by ultrasonic treatment and centrifugation. The obtained nanostructures preserve BP column dimensions, forming...
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Synchronized six-step voltage generation in high-speed PMSM drive
PublicationSynchronized voltage generation has already been considered in the context of pulse width modulation (PWM). References prove that synchronized PWM substantially decreases subharmonics in inverter output voltage when operating with low switching-to-fundamental frequency ratio. This paper identifies problems of unsynchronized voltage generation in electric drives under six-step inverter operation. Guidelines for the synchronization...
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Analysis of Measurement Errors in Rail Vehicles’ Pantograph Inspection System
PublicationThe paper presents an approach to evaluation of height measurement errors in laser scanning inspection system. The system, consisting of a laser line generator and a specialized camera, is dedicated to diagnosing carbon contact strips of railway vehicles’ pantographs. While height measurement resolution is easily computable based on system parameters, determining the measurement error is troublesome due to numerous impacts. As...
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Experimental investigations of damage evolution in concrete during bending by continuous micro-CT scanning
PublicationThe paper describes experimental investigation results of fracture in notched concrete beams under quasi-static three-point bending. To visualize 3D fracture in concrete under bending, an extended X-ray micro-computed tomography system was used, i.e. the tomography system SkyScan 1173 was connected to the loading machine ISTRON 5569. This combined system enabled to shot images of deforming concrete beams during a continuous deformation...
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Tensile test results of fused filamend fabricated polylactyde and polylactyde with carbon fiber filler
Open Research DataThe Dataset contains the results of the mechanical behaviour of dog-bone shaped specimens. The specimens were additively manufactured with the fused filament fabrication (FFF) method. They used two different materials polylactide (PURE PLA) and polylactide with carbon fibre filler (PLA+CF). The specimens were segregated into three groups - unsterilized,...
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Bricks images dataset
Open Research DataThe set contains 200 images of various wooden bricks of various shapes and colors placed on a background (blanket) with some heart shaped patterns. Each photo is available in 300x300 and 224x224 pixels size in PNG format. Photos are divided in 10 classes – 8 types of bricks photographed form various angles + 2 additional classes (multiple bricks at...
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Are you a Strategic Thinker? Summer 21/22 - Nowy
e-Learning CoursesThe course explores strategic management choices along with the role of innovation in creating sustainable competitive advantage. It introduces frameworks and tools of strategic management (e.g. how to analyze organizations in their industry context and how to design and execute a coherent strategy). Concepts such as value creation, product diversification, clustering and open innovation will be explored to understand how entrepreneurs...
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Are you a Strategic Thinker? Summer 22/23
e-Learning CoursesThe course explores strategic management choices along with the role of innovation in creating sustainable competitive advantage. It introduces frameworks and tools of strategic management (e.g. how to analyze organizations in their industry context and how to design and execute a coherent strategy). Concepts such as value creation, product diversification, clustering and open innovation will be explored to understand how entrepreneurs...
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Are you a Strategic Thinker? WINTER 23/24
e-Learning CoursesThe course explores strategic management choices along with the role of innovation in creating sustainable competitive advantage. It introduces frameworks and tools of strategic management (e.g. how to analyze organizations in their industry context and how to design and execute a coherent strategy). Concepts such as value creation, product diversification, clustering and open innovation will be explored to understand how entrepreneurs...
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Are you a Strategic Thinker? WINTER 24
e-Learning CoursesThe course explores strategic management choices along with the role of innovation in creating sustainable competitive advantage. It introduces frameworks and tools of strategic management (e.g. how to analyze organizations in their industry context and how to design and execute a coherent strategy). Concepts such as value creation, product diversification, clustering and open innovation will be explored to understand how entrepreneurs...
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Are you a Strategic Thinker? SUMMER 23/24
e-Learning CoursesThe course explores strategic management choices along with the role of innovation in creating sustainable competitive advantage. It introduces frameworks and tools of strategic management (e.g. how to analyze organizations in their industry context and how to design and execute a coherent strategy). Concepts such as value creation, product diversification, clustering and open innovation will be explored to understand how entrepreneurs...
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Uwarunkowania i dylematy polityki regionalnej na obszarze peryferyjnym województwa pomorskiego
PublicationIstnieją duże różnice w poziomie rozwoju między obszarami metropolitalnymi a obszarami poza nimi, czyli peryferyjnymi. Różnice te dotyczą również czynników i szans rozwoju. Autor ocenia czynniki rozwojowe w powiatach na obszarze peryferyjnym województwa pomor-skiego. Analizuje też uwarunkowania przestrzenne rozwoju obszaru. Za ważne uwarunkowa-nie uznaje dystans 30 km jako akceptowalny dla dojazdów do pracy. Wynika z niego, że...
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Fluctuation of nitrogen fraction during wastewater treatment in a multistage treatment wetland
PublicationFactors influencing COD and removal and transformation of N fractions have been investigatedin the conditions of horizontal (SSHF) and vertical (SSVF) flow reed beds. Multistage treatment wetlandin Wiklino ensured a stable and very effective removal of all the analysed pollutants. Based onthe resultsof investigation, it could be assumed that the working conditions of SSHF beds play an importantrole in the transformation of particulate...
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Spectral reflectance modeling of ZnO layers made with Atomic Layer Deposition for application in optical fiber Fabry-Perot interferometric sensors
PublicationSuitability of zinc oxide (ZnO) layers grown using Atomic Layer Deposition for operation in optical-fiber extrinsic Fabry-Perot sensors is investigated using a numerical model. Reflectance spectra obtained using the developed model indicate that the application of these layers in optical-fiber extrinsic Fabry-Perot sensors is difficult as it may require a source whose spectrum width is about 300 nm. A series of ZnO layers grown...
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The instantaneous frequency rate spectogram
PublicationAn accelerogram of the instantaneous phase of signal components referred to as an instantaneous frequency rate spectrogram (IFRS) is presented as a joint time-frequency distribution. The distribution is directly obtained by processing the short-time Fourier transform (STFT) locally. A novel approach to amplitude demodulation based upon the reassignment method is introduced as a useful by-product. Additionally, an estimator of energy...
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Classification of Sea Going Vessels Properties Using SAR Satellite Images
PublicationThe aim of the project was to analyze the possibility of using machine learning and computer vision to identify (indicate the location) of all sea-going vessels located in the selected area of the open sea and to classify the main attributes of the vessel. The key elements of the project were to download data from the Sentinel-1 satellite [1], download data on the sea vessels [2], then automatically tag data and develop a detection...
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A method of predicting the best conditions for large-size workpiece clamping to reduce vibration in the face milling process
PublicationThe paper presents an innovative method of solving the problem of vibration suppression during milling of large-size details. It consists in searching for the best conditions for clamping the workpiece based on a rapid modal identification of the dominant natural frequencies only and requires repetitive changes in the tightening torque of the clamping screws. Then, by estimating the minimum work of the cutting forces acting in...
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Application of Barycentric Coordinates in Space Vector PWM Computations
PublicationThis paper proposes the use of barycentric coordinates in the development and implementationof space-vector pulse-width modulation (SVPWM) methods, especially for inverters with deformed space-vector diagrams. The proposed approach is capable of explicit calculation of vector duty cycles, independentof whether they assume ideal positions or are displaced due to the DC-link voltage imbalance. The use ofbarycentric coordinates also...
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Residual MobileNets
PublicationAs modern convolutional neural networks become increasingly deeper, they also become slower and require high computational resources beyond the capabilities of many mobile and embedded platforms. To address this challenge, much of the recent research has focused on reducing the model size and computational complexity. In this paper, we propose a novel residual depth-separable convolution block, which is an improvement of the basic...
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Flow Boiling in Minigap in the Reversed Two-Phase Thermosiphon Loop
PublicationThe paper presents the results of experimental investigations of a model of a heat exchanger featuring a minigap, which is perceived as an evaporator for an inverted thermosiphon. The system works with a single component test fluid. The tested evaporator generates pumping power in the test loop in a way similar to the mammoth pump. The tests regarded a module of the heat exchanger, consisting of a hot leg and a cold leg with the...
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High Temperature Drying Process of Beech Wood (Fagus sylvatica L.) with Different Zones of Sapwood and Red False Heartwood
PublicationThis study examined the changes in the properties of beech wood (Fagus sylvatica L.) after intense drying. Beech wood with false red heartwood was selected as the test specimen. The test samples had dimensions of 50 mm thickness, 180 mm width, and 350 mm length. The specimens were divided into two groups, false red heartwood and sapwood. These specimens were selected with different angles of the growth rings (radial and tangential)....
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Anita Mieszkowska, ETI (Tel) , II sem. 2023/2024l
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Transiluminacyjne monitorowanie stanu przestrzeni podpajęczynówkowej
PublicationTransiluminacja tkanek ludzkiego ciała w celach diagnostycznych jest stosowana od ponad stu lat. Metoda transiluminacji w bliskiej podczerwieni z rozpraszaniem zwrotnym (NIRT-BSS) umożliwia ciągłe, bezinwazyjne monitorowanie zmian szerokości przestrzeni podpajęczynówkowej, które może być cennym narzędziem w ocenie zagrożenia obrzękiem mózgu. W rozprawie przedstawiono optyczny model rozchodzenia się promieniowania podczerwonego...
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Data from 76- to 81-GHz mmWave Sensor located at S7 road
Open Research DataThe set consists data recorded employing IWR1642 mmWave sensor from Texas Instruments. The purpose of the experiment was to detect vehicles and their speed in real conditions – at S7 road, near Dworek village (54°14'40.0"N 18°59'59.0"E).
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Amplitude-distance spectroscopy in semi-contact mode
Open Research DataSince it was invented by Binnig et al. in 1986, atomic force microscopy (AFM) plays a key role in science and technology at the nanoscale. AFM is a microscopic technique that visualizes the surface topography using the attractive and repulsive forces of interaction between several atoms (in theory) of a blade attached to the end of the probe lever and...
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NUMERICAL MODEL QUALITY ASSESSMENT OF OFFSHORE WIND TURBINE SUPPORTING STRUCTURE BASED ON EXPERIMENTAL DATA
PublicationAs a structure degrades some changes in its dynamical behavior can be observed, and inversely, observation and evaluation of these dynamical changes of the structure can provide information of structural state of the object. Testing of the real structure, besides of being costly, can cover only limited working states. It is particularly considerable in case of hardly accessible, and randomly/severely dynamically loaded offshore...
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Experience of hybrid constructed wetlands operation in Gdansk region
PublicationThe investigation were carried out at five local hybrid constructed wetlands (HCWs), which secured biological treatment of domestic wastewater generated from 15 to 600 pe. Based on over two years monitoring it was indicated that HCWs ensured very effective removal of organic matter from 74.9 to 95.5 COD % in wild range of loadings (1.5 - 17.0g COD/ m3day). Efficiency of total nitrogen removal varied significantly from 23.4 two...
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Biomechanics of the medial meniscus in the osteoarthritic knee joint
PublicationBackground. Increased mechanical loading and pathological response of joint tissue to the abnormal mechanical stress can cause degradation of cartilage characteristic of knee osteoarthritis (OA). Despite osteoarthritis is risk factor for the development of meniscal lesions the mechanism of degenerative meniscal lesions is still unclear. Therefore, the aim of the study is to investigate the influence of medial compartment knee OA...
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Infiltration in a double-porosity medium: Experiments and comparison with a theoretical model
PublicationThis paper presents experimental verification of the mathematical model of unsaturated flow in double‐porosity soils developed by the asymptotic homogenization method. A series of one‐dimensional infiltration experiments was carried out in a column filled with a double‐porosity medium composed of a mixture of sand and sintered clayey spheres arranged in a periodic manner. The unsaturated hydraulic properties of each porous material...
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Efficiency of Wastewater Treatment in Single-Family Constructed Wetlands in Kaszuby Lake District
PublicationIn the paper results of investigation upon three different configurations of single family treatment wetlands were presented. It was indicated that the application of treatment wetlands for single family effluent is a effective and sustainable solution for wastewater treatment in the rural areas. In spite of the receiving higher concentration of pollutants in comparison to the TWs operated in Europe and USA analysed TWs ensure...
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ON DYNAMICS OF ELASTIC NETWORKS WITH RIGID JUNCTIONS WITHIN NONLINEAR MICRO-POLAR ELASTICITY
PublicationWithin the nonlinear micropolar elasticity we discuss effective dynamic (kinetic) properties of elastic networks with rigid joints. The model of a hyperelastic micropolar continuum is based on two constitutive relations, i.e., static and kinetic ones. They introduce a strain energy density and a kinetic energy density, respectively. Here we consider a three-dimensional elastic network made of three families of elastic fibers connected...
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Efficiency of pollutant removal by five multistage constructed wetlands in a temperate climate
PublicationIn recent years, an increase in interest in hybrid constructed wetland systems (HCWs) has beenobserved. These systems are composed of two or more filters with different modes of sewage flow.Based on over eight years of monitoring, carried out at five local HCWs located in the PomeraniaRegion of Northern Poland, the effective removal of organic matter (from 74.9 to 95.5% COD) in theloading range 1.5-17.0 g COD·m-2·d-1 was confirmed....
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'21/'22 Fakty i mity na temat żywności – od historii, która zabija po kanapowców-smartfonowców [PG_00057828]
e-Learning CoursesOd koczownictwa po GMO. 200 tysięcy lat bez lodówki. Głód i niewłaściwe odżywianie się - najwięksi ludobójcy w dziejach człowieka. Funkcjonowanie i rozwój ludzkości możliwy dzięki owocom największej rewolucji w swoich dziejach: rolnictwa. Przemiany gospodarcze, społeczne, polityczne, obyczajowe, etyczne, które następowały wraz z rozwojem rolnictwa. Technologiczny aspekt rozwoju produkcji żywności. Wykwintna kuchnia francuska...
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The role of numerical tests in assessing road restraint system functionality
PublicationKey to understanding the needs and building road infrastructure management tools to prevent and mitigate run-off-road accidents is to identify hazards and their sources which are a result of wrong design, construction, and installation of road restraint systems. Building such tools requires advanced studies with field tests, simulations and models to demonstrate the effects of selected parameters on road user safety. The research...